IVF Transfer of Fresh or Frozen Embryos in Women without Polycystic Ovaries

Embryo transfer impact: a comprehensive national cohort analysis comparing maternal and neonatal outcomes across varied embryo stages in fresh and frozen transfers

Introduction

The utilization of frozen embryo transfer not only enhances reproductive outcomes by elevating the likelihood of live birth and clinical pregnancy but also improves safety by mitigating the risks associated with ovarian hyperstimulation syndrome (OHSS) and multiple pregnancies. There has been an increasing debate in recent years regarding the advisability of making elective frozen embryo transfer the standard practice. Our study aims to determine the optimal choice between fresh and frozen embryo transfer, as well as whether the transfer should occur at the cleavage or blastocyst stage.

Method

In this retrospective cohort study conducted in Taiwan, data from the national assisted reproductive technology (ART) database spanning from January 1st, 2013, to December 31st, 2017, were analyzed. The study included 51,762 eligible female participants who underwent ART and embryo transfer. Pregnancy outcomes, maternal complications, and singleton neonatal outcomes were evaluated using the National Health Insurance Database from January 1st, 2013, to December 31st, 2018. Cases were categorized into groups based on whether they underwent fresh or frozen embryo transfers, with further subdivision into cleavage stage and blastocyst stage transfers. Exposure variables encompassed clinical pregnancy rate, live birth rate, OHSS, pregnancy-induced hypertension, gestational diabetes mellitus (DM), placenta previa, placental abruption, preterm premature rupture of membranes (PPROM), gestational age, newborn body weight, and route of delivery.

Results

Frozen blastocyst transfers showed higher rates of clinical pregnancy (CPR) and live births (LBR) compared to fresh blastocyst transfers. Conversely, frozen cleavage stage transfers demonstrated lower rates of clinical pregnancy and live birth compared to fresh cleavage stage transfers. Frozen embryo transfers were associated with reduced risks of OHSS but were linked to a higher risk of pregnancy-induced hypertension compared to fresh embryo transfers. Additionally, frozen embryo transfers were associated with a higher incidence of large for gestational age infants and a lower incidence of small for gestational age infants.

Conclusion

The freeze-all strategy may not be suitable for universal application. When embryos can develop to the blastocyst stage, FET is a favorable choice, but embryos can only develop to the cleavage stage, fresh embryo transfer becomes a more reasonable option.

When to randomize patients in a randomized controlled trial?

The timing of randomization should be considered carefully in the context of each trial because it has implications for the particular research question answered. In most instances, randomization should be delayed until as close as practically possible to the moment of intervention. In some cases, early randomization may offer certain advantages, but trialists should balance these, including any administrative complexity or inconvenience, against the risk of avoidable protocol violations and avoidable drop out.

Can serum progesterone concentration direct a fresh or freeze-all transfer strategy in the first in vitro fertilisation cycle?

PURPOSE

To examine the interaction between serum progesterone concentration on the trigger day and choice of freeze-all and fresh transfer strategies on live birth in an unselected population as well as in patients over 35 years old.

METHODS

We performed a retrospective cohort study of 26,661 patients commencing their first IVF cycle in a large fertility centre between 2015 and 2019, including 4687 patients over 35 years old. We performed a multivariable fractional polynomial interaction analysis within a logistic regression model to investigate the interaction between serum progesterone concentration and the choice of freeze-all or fresh transfer strategy following the first transfer.

RESULTS

15,539 patients underwent a fresh embryo transfer and 11,122 underwent a freeze-all strategy in their first IVF cycle. The freeze-all group had a higher live birth rate compared to the fresh group (43.9% vs 40.3%). After adjusting for confounding factors, there was a positive interaction between serum progesterone concentrations and the choice of a freeze-all versus fresh embryo transfer on live birth (p for interaction 0.0001), with a larger magnitude of effect when progesterone concentration was higher. Such an interaction was also observed in patients over 35 years old (p for interaction 0.01), but the treatment effect curve over progesterone concentrations was almost flat.

CONCLUSIONS

In an unselected population, frozen transfer is associated with greater chances of live birth, especially in patients with higher serum progesterone concentration. In patients over 35 years old, the benefit of a freeze-all policy appears small across all serum progesterone concentrations.

Assessing obstetric outcomes: A systematic review and meta-analysis comparing fresh, artificial, and natural thaw embryo transfer cycles

BACKGROUND

The increasing utilisation of in vitro fertilisation (IVF) has prompted significant interest in determining the optimal endometrial environment to increase pregnancy rates and minimise the obstetric complications associated with various embryo transfer strategies.

AIMS

To determine which cycle is associated with increased obstetric complications: fresh embryo transfer (FreshET), natural thaw (NatThawET) or artificial thaw (ArtThawET). Outcomes of interest included: hypertensive disorders of pregnancy (HDP), gestational diabetes (GD), pre-term birth (PTB), post-partum haemorrhage (PPH) and large for gestational age (LGA).

MATERIALS AND METHODS

A comprehensive search of MEDLINE, EMBASE, CENTRAL, and PUBMED was conducted from 1947 to May 17, 2022. Two independent reviewers carried out the screening, and data extraction for the following comparisons: ArtThawET vs NatThawET, ArtThawET vs FreshET, and NatThawET vs FreshET. Meta-analysis was conducted using a fixed-effect Mantel-Haenszel model. The quality of the studies was assessed using GRADEpro.

RESULTS

A total of 23 studies were included in this review. ArtThawET was associated with a significantly increased odds of HDP (odds ratio (OR) 1.76, confidence interval (CI) 1.66-1.86), PTB (OR 1.18, CI 1.13-1.23), PPH (OR 2.61, CI 2.3-2.97) and LGA (OR 1.11, CI 1.07-1.15), compared to NatThawET. ArtThawET was also associated with increased odds of HDP (OR 2.13, CI 1.89-2.4), PPH (OR 3.52, CI 3.06-4.04) and LGA (OR 2.12, CI 1.77-2.56), compared to FreshET. Furthermore, NatThawET demonstrated increased odds of HDP (OR 1.20, CI 1.11-1.29), PPH (OR 1.25, CI 1.14-1.38) and LGA (OR 1.85, CI 1.66-2.07) compared to FreshET.

CONCLUSION

When clinically feasible, ArtThawET should be avoided as a first-line option for IVF to reduce the risk of obstetric complications. An adequately powered, multicentre randomised controlled trial is necessary to confirm these findings and investigate the underlying pathophysiology.

Luteal phase support in assisted reproductive technology

Infertility affects one in six couples, with in vitro fertilization (IVF) offering many the chance of conception. Compared to the solitary oocyte produced during the natural menstrual cycle, the supraphysiological ovarian stimulation needed to produce multiple oocytes during IVF results in a dysfunctional luteal phase that can be insufficient to support implantation and maintain pregnancy. Consequently, hormonal supplementation with luteal phase support, principally exogenous progesterone, is used to optimize pregnancy rates; however, luteal phase support remains largely 'black-box' with insufficient clarity regarding the optimal timing, dosing, route and duration of treatment. Herein, we review the evidence on luteal phase support and highlight remaining uncertainties and future research directions. Specifically, we outline the physiological luteal phase, which is regulated by progesterone from the corpus luteum, and evaluate how it is altered by the supraphysiological ovarian stimulation used during IVF. Additionally, we describe the effects of the hormonal triggers used to mature oocytes on the degree of luteal phase support required. We explain the histological transformation of the endometrium during the luteal phase and evaluate markers of endometrial receptivity that attempt to identify the 'window of implantation'. We also cover progesterone receptor signalling, circulating progesterone levels associated with implantation, and the pharmacokinetics of available progesterone formulations to inform the design of luteal phase support regimens.

Clinical outcomes after fresh versus frozen embryo transfer in women with advanced reproductive age undergoing in vitro fertilization: a propensity score-matched cohort study

This retrospective cohort study aimed to compare clinical outcomes following fresh or frozen embryo transfer (FET) in women with advanced reproductive age (ARA). Women aged 35-45 years who underwent their first autologous fresh or frozen cleavage stage embryo transfer cycle in the Centre for Assisted Reproduction of Shanghai First Maternity and Infant Hospital between January 2016 and December 2020 were included. The primary outcome was live birth after the first embryo transfer of the in vitro fertilization (IVF) cycle. Multiple covariates were used for propensity score matching (PSM) and generalized estimating equations were performed to examine the independent association between FET and live birth. Of the total 1453 patients, 327 patients had FET and 1126 patients had fresh ET. After the PSM procedure, 274 patients were included in each group. The live birth rate was 24.8% in the FET group and 25.2% in the fresh ET group (OR 0.98, 95% CI: 0.67-1.44, P = 0.92). Other pregnancy, perinatal and neonatal outcomes were all comparable between the two groups. This study showed that FET did not improve live birth and other clinical outcomes as compared with fresh embryo transfer in women with ARA who underwent their first IVF cycle.

Progestogens for prevention of luteinising hormone (LH) surge in women undergoing controlled ovarian hyperstimulation as part of an assisted reproductive technology (ART) cycle

BACKGROUND

Currently, gonadotrophin releasing hormone (GnRH) analogues are used to prevent premature ovulation in ART cycles. However, their costs remain high, the route of administration is invasive and has some adverse effects. Oral progestogens could be cheaper and effective to prevent a premature LH surge.

OBJECTIVES

To evaluate the effectiveness and safety of using progestogens to avoid spontaneous ovulation in women undergoing controlled ovarian hyperstimulation (COH).

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group trials register, CENTRAL, MEDLINE, Embase and PsycINFO in Dec 2021. We contacted study authors and experts to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that included progestogens for ovulation inhibition in women undergoing controlled ovarian hyperstimulation (COH).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane, including the risk of bias (RoB) assessment. The primary review outcomes were live birth rate (LBR) and oocyte pick-up cancellation rate (OPCR). Secondary outcomes were clinical pregnancy rate (CPR), cumulative pregnancy, miscarriage rate (MR), multiple pregnancies, LH surge, total and MII oocytes, days of stimulation, dose of gonadotropins, and moderate/severe ovarian hyperstimulation syndrome (OHSS) rate. The primary analyses were restricted to studies at overall low and some concerns RoB, and sensitivity analysis included all studies. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 14 RCTs (2643 subfertile women undergoing ART, 47 women used oocyte freezing for fertility preservation and 534 oocyte donors). Progestogens versus GnRH antagonists We are very uncertain of the effect of medroxyprogesterone acetate (MPA) 10 mg compared with cetrorelix on the LBR in poor responders (odds ratio (OR) 1.25, 95% confidence interval (CI) 0.73 to 2.13, one RCT, N = 340, very-low-certainty evidence), suggesting that if the chance of live birth following GnRH antagonists is assumed to be 18%, the chance following MPA would be 14% to 32%. There may be little or no difference in OPCR between progestogens and GnRH antagonists, but due to wide Cs (CIs), we are uncertain (OR 0.92, 95%CI 0.42 to 2.01, 3 RCTs, N = 648, I² = 0%, low-certainty evidence), changing the chance of OPCR from 4% with progestogens to 2% to 8%. Given the imprecision found, no conclusions can be retrieved on CPR and MR. Low-quality evidence suggested that using micronised progesterone in normo-responders may increase by 2 to 6 the MII oocytes in comparison to GnRH antagonists. There may be little or no differences in gonadotropin doses. Progestogens versus GnRH agonists Results were uncertain for all outcomes comparing progestogens with GnRH agonists. One progestogen versus another progestogen The analyses comparing one progestogen versus another progestogen for LBR did not meet our criteria for primary analyses. The OPCR was probably lower in the MPA 10 mg in comparison to MPA 4 mg (OR 2.27, 95%CI 0.90 to 5.74, one RCT, N = 300, moderate-certainty evidence), and MPA 4 mg may be lower than micronised progesterone 100 mg, but due to wide CI, we are uncertain of the effect (OR 0.81, 95%CI 0.43 to 1.53, one RCT, N = 300, low-certainty evidence), changing the chance of OPCR from 5% with MPA 4 mg to 5% to22%, and from 17% with micronised progesterone 100 mg to 8% to 24%. When comparing dydrogesterone 20 mg to MPA, the OPCR is probably lower in the dydrogesterone group in comparison to MPA 10 mg (OR 1.49, 95%CI 0.80 to 2.80, one RCT, N = 520, moderate-certainty evidence), and it may be lower in dydrogesterone group in comparison to MPA 4 mg but due to wide confidence interval, we are uncertain of the effect (OR 1.19, 95%CI 0.61 to 2.34, one RCT, N = 300, low-certainty evidence), changing the chance of OPCR from 7% with dydrogesterone 20 to 6-17%, and in MPA 4 mg from 12% to 8% to 24%. When comparing dydrogesterone 20 mg to micronised progesterone 100 mg, the OPCR is probably lower in the dydrogesterone group (OR 1.54, 95%CI 0.94 to 2.52, two RCTs, N=550, I² = 0%, moderate-certainty evidence), changing OPCR from 11% with dydrogesterone to 10% to 24%. We are very uncertain of the effect in normo-responders of micronised progesterone 100 mg compared with micronised progesterone 200 mg on the OPCR (OR 0.35, 95%CI 0.09 to 1.37, one RCT, N = 150, very-low-certainty evidence). There is probably little or no difference in CPR and MR between MPA 10 mg and dydrogesterone 20 mg. There may be little or no differences in MII oocytes and gonadotropins doses. No cases of moderate/severe OHSS were reported in most of the groups in any of the comparisons.

AUTHORS' CONCLUSIONS

Little or no differences in LBR may exist when comparing MPA 4 mg with GnRH agonists in normo-responders. OPCR may be slightly increased in the MPA 4 mg group, but MPA 4 mg reduces the doses of gonadotropins in comparison to GnRH agonists. Little or no differences in OPCR may exist between progestogens and GnRH antagonists in normo-responders and donors. However, micronised progesterone could improve by 2 to 6 MII oocytes. When comparing one progestogen to another, dydrogesterone suggested slightly lower OPCR than MPA and micronised progesterone, and MPA suggested slightly lower OPCR than the micronised progesterone 100 mg. Finally, MPA 10 mg suggests a lower OPCR than MPA 4 mg. There is uncertainty regarding the rest of the outcomes due to imprecision and no solid conclusions can be drawn.

An appraisal of current embryo transfer strategies

Embryo transfer, one of the most essential procedures in assisted reproductive technology, plays a vital role in the success of in-vitro fertilization and intracytoplasmic sperm injection. During the last decades, the strategies for embryo transfer have changed dramatically. In this review, we evaluate the efficacy and safety of several current embryo transfer strategies including fresh versus frozen embryo transfer, cleavage- versus blastocyst-stage embryo transfer, and single- versus double-embryo transfer. Available evidence indicates that the freeze-only strategy improves the live birth rate after the first embryo transfer in high responders while making no difference in normal responders. The risk of ovarian hyperstimulation syndrome is significantly reduced in the freeze-only strategy. Fresh blastocyst-stage embryo transfer increased live birth rate compared to cleavage-stage embryo transfer. The best embryo transfer strategy is one which tailors to individual circumstances and preferences.

Limited Effects of Ultra-low Oxygen Concentration during Extended Embryo Culture on In vitro Fertilisation Outcomes in Indian Women: A Retrospective Cross-sectional Study

Background

Amongst various other factors, oxygen (O2) concentration in embryo culture plays an important role in determining pregnancy outcomes in women undergoing in vitro fertilisation. Some studies have reported that lowering O2 levels in embryo culture provides better results.

Aims

To explore the effects of low- and ultra-low- O2 concentrations (5% and 2%, respectively) in extended embryo culture on various outcome parameters of pregnancy.

Settings and Design

This was a retrospective cross-sectional study.

Materials and Methods

In this study 382 participants had their embryos cultured in varying O2 concentrations (5% or 2%), followed by either a fresh embryo transfer (ET) or frozen embryo transfer (FET). Outcomes such as pregnancy rate, implantation rate, abortion rate, twinning rate, and live birth rate were compared between the groups.

Statistical Analysis Used

Chi square test was applied to compare the primary and secondary outcomes between different groups.

Results

No significant differences were observed in pregnancy rate and implantation rate between 5% and 2% O2 groups, irrespective of their mode of ET. The abortion rate was significantly higher in 5% O2 group than in 2% group during FET (24.71% vs. 11.49%, P = 0.02). While the proportion of good-quality embryos was higher in 5% O2 group, these did not translate to better pregnancy outcomes. Additionally, embryos cultured in 2% O2 concentration had a significantly better implantation rate when they were transferred fresh rather than frozen (71.34% vs. 61.46%, P = 0.04). There were no other differences observed.

Conclusion

Only marginal benefits were observed in switching human embryos to ultra-low O2 concentration after the initial days of culture.

Large-scale retrospective analysis of methodological factors affecting pregnancy rates after embryo transfer for in vitro fertilization

This study aimed to investigate the impact of methodological factors on pregnancy rates after embryo transfer (ET) for in vitro fertilization. This retrospective cross-sectional study was conducted between September 2020 and April 2022. A total of 2048 patients who underwent ultrasonography-guided first frozen embryo transfer (FET) or a fresh ET cycle due to infertility were included in the study. The effects of age, ET protocol (frozen or fresh), preimplantation genetic testing, number of embryos transferred (NET), and embryo fundus distance on pregnancy rate were investigated. The mean age of pregnant patients (31.51 ± 5.28) was significantly lower than that of non-pregnant patients (35.34 ± 6.39) (P < .001). Multiple regression analysis showed that women with lower age (P < .001), higher NET (P < .001), higher embryo fundus distance (P < .001), FET (P < .001), and preimplantation genetic testing (P = .012) had a significantly higher likelihood of pregnancy. Appropriate transfer depth, younger age, euploid embryo transfer, FET, and a higher NET can increase the likelihood of pregnancy. However, multiple factors must be considered when deciding the best protocol for a particular patient, including patient preference, costs and timing.

Outcomes of the Next In Vitro Fertilization Cycle in Women with Polycystic Ovary Syndrome after a Failed In Vitro Maturation Attempt

BACKGROUND

In vitro maturation (IVM) is indicated in women with polycystic ovary syndrome (PCOS) who have a very good ovarian response during in vitro fertilization (IVF) and are therefore at high risk of ovarian hyperstimulation syndrome (OHSS). According to the latest practice committee document, IVM could be a major advance in assisted reproductive technology (ART) procedures (reduced cost and simplified treatment); nevertheless, retrospective studies of IVM versus IVF still demonstrate lower chances of a live birth with IVM. Could IVM prove to be an optimal first-line treatment approach? And limited information is available concerning the success of the subsequent IVF cycle after the failure of an IVM cycle. Does IVM treatment adversely affect the subsequent IVF cycle, and is this worth considering before performing the IVF cycle for women with PCOS?

METHODS

This prospective nested case-control study at the Peking University Reproductive Medicine center in China was performed between March 2018 and September 2020. Women aged 20-38 years with PCOS and infertility and who were scheduled for their first IVF attempt were eligible. A total of 351 women were randomly allocated to receive one cycle of unstimulated natural IVM (n = 175) or one cycle of standard IVF with a flexible GnRH antagonist protocol followed by hCG as an ovulation trigger (n = 176). This study involved 234 women (58 women with no blastocysts in the first IVM cycle and 158 women who underwent the first IVF cycle). Cumulative live birth rate at 12 months after oocyte retrieval and OHSS of a standard controlled ovarian stimulation (COS) IVF cycle were compared between 58 women in an IVF cycle following a failed IVM cycle and 158 women who underwent the first IVF cycle.

RESULTS

No significant differences were found in the cumulative live birth rate (CLBR), ongoing pregnancy rate, or clinical pregnancy rate at 12 months after oocyte retrieval between the two groups (56.9% vs. 58.9%, p = 0.795; 58.6% vs. 60.8%, p = 0.776; and 84.5% vs. 76.0%, p = 0.178). The incidence of moderate-to-severe OHSS was not significantly different between the groups (6.9% vs. 5.7%, p = 0.742). Additionally, there were no significant differences in the total gonadotropin dose, stimulation duration, number of retrieved oocytes, number of retrieved mature oocytes, or fertilization rates.

CONCLUSIONS

Even if the first IVM attempt failed in subfertile women with PCOS, comparable cumulative live birth rates were observed in the subsequent IVF cycle. IVM treatment does not adversely affect the subsequent IVF cycle.

Obstetric and perinatal outcomes after embryos cultured in one-step versus sequential culture media systems in vitrified-warmed single blastocyst transfer cycles

RESEARCH QUESTION

Does type of culture medium used influence obstetric and perinatal outcomes after vitrified-warmed single blastocyst transfers?

DESIGN

Retrospective cohort study involving singletons after vitrified-warmed single blastocyst embryo transfers, using embryos cultured in either Irvine Continuous Single Culture medium (CSC) or Vitrolife G5TM PLUS medium culture system between 2013 and 2020.

RESULTS

A total of 2475 women who had singleton deliveries were included for final analysis: 1478 had embryos cultured in CSC and 997 had embryos cultured in G5TM PLUS medium. Birth outcomes, including preterm birth, mean birth weight, gestational age- and sex-adjusted birth weight (Z-scores), rates of large-for-gestational-age, small-for-gestational-age, low birth weight and macrosomia, and the distribution of newborn gender did not differ significantly between groups in crude and adjusted analyses. Women whose embryos were cultured in G5TM PLUS frequently suffered from pregnancy-induced hypertensive disorders compared with those who had embryos cultured in CSC (4.7% versus 3.0%; P = 0.031). This difference was no longer significant after adjusting for several key confounders (adjusted odds ratio 1.49, 95% CI 0.94 to 2.38, P = 0.087). Other obstetric complications, including gestational diabetes mellitus, preterm premature rupture of membranes, abnormal placentation, postpartum haemorrhage and the mode of delivery were all similar between the two groups.

CONCLUSIONS

The present study adds new information to the current evidence by suggesting that the embryo culture medium does not affect birth outcomes and obstetric complications when comparison is limited to Irvine CSC and Vitrolife G5TM PLUS in vitrified-warmed single blastocyst transfer cycles.

Reproductive history does not compromise subsequent live birth and perinatal outcome following in-vitro fertilization: analysis of 25 329 first frozen-thawed embryo transfer cycles without preimplantation genetic testing for aneuploidy

OBJECTIVE

To investigate the effect of women's reproductive history on live-birth rate and perinatal outcome after first frozen-thawed embryo transfer (FET) without preimplantation genetic testing for aneuploidy.

METHODS

This was a retrospective cohort study of women who had undergone their first FET cycle between January 2014 and December 2020 at a university-affiliated fertility center. No transferred embryo underwent preimplantation genetic testing for aneuploidy. The women were categorized into five groups based on their reproductive history: no previous pregnancy; previous termination of pregnancy (TOP); previous pregnancy loss; previous ectopic pregnancy (EP); and previous live birth. The women with no previous pregnancy were considered as the reference group. The primary outcome was the live-birth rate and secondary endpoints included rates of positive pregnancy test, clinical pregnancy, pregnancy loss and EP as well as perinatal outcomes such as birth weight and preterm birth. Multivariable logistic regression analyses were used to control for a number of potential confounders, including age, body mass index, education level, duration and cause of infertility, insemination method, type of endometrial preparation, number of embryos transferred, embryo developmental stage, quality of the embryos transferred, year of treatment and endometrial thickness. Additionally, propensity score matching (PSM) was used to check the robustness of the main findings.

RESULTS

In total, 25 329 women were included in the final analysis. On univariate analysis, each reproductive-history type except for previous EP was significantly associated with worse pregnancy outcome following in-vitro fertilization (IVF), including rates of positive pregnancy test, clinical pregnancy, pregnancy loss and live birth, when compared with the group of women with no previous pregnancy. However, after correcting for several potential confounders, the differences in rates of live birth, pregnancy loss, positive pregnancy test and clinical pregnancy were no longer significant between the study and control groups on multivariable regression models, while the risk of EP after embryo transfer was elevated among women with a previous TOP or EP. There was no increased risk of adverse perinatal outcome associated with reproductive history compared with the control group. Notably, similar results were obtained from the PSM models, confirming the robustness of the main findings.

CONCLUSION

Relative to women without a previous pregnancy, those with a prior TOP, pregnancy loss, EP or live birth did not have compromised live-birth rate or perinatal outcomes following FET without preimplantation genetic testing for aneuploidy, with the exception of an increased risk of EP in those with prior TOP or EP. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Effect of basal luteinizing hormone (bLH) level on in vitro fertilization/intra-cytoplasmic injections (IVF/ICSI) outcomes in polycystic ovarian syndrome (PCOS) patients

OBJECTIVE

To evaluate the effect of basal luteinizing hormone (bLH) levels on In Vitro Fertilization/Intra-Cytoplasmic Injections (IVF/ICSI) outcomes in polycystic ovary syndrome (PCOS).

METHODS

A total of 256 PCOS patients who underwent IVF/ICSI treatment in our center from January 2018 to January 2022 were analyzed retrospectively. The patients were based on the third quartile (12.455) of the basal LH value was taken as the cut-off value and was divided into high and low LH group: high LH group (LH ≥ 12.455 IU / L) and low LH group (LH < 12.455 IU / L) and the OC group was pretreated with oral contraceptives. The outcomes in ovulation induction and embryo transfer cycles of the three groups were then compared. In addition, factors influencing the number of good quality embryos and the early onset LH peak were analyzed.

RESULTS

Ages, infertility duration, body mass index (BMI), and basal follicle-stimulating hormone (FSH), and progesterone (P), testosterone (T) levels were not significantly different among the three groups (p > 0.05). However,there were significant differences in basal LH and basal E2 between low LH group and high LH group, and there were significant differences in basal LH between high LH group and OC group (p < 0.05). LH on the antagonist day was significantly different between low LH group and high LH group and between high LH group and OC group (p < 0.05). LH on the hCG (human Chorionic Gonadotropin) day there were significant differences between low LH group and OC group, high LH group and OC group (p < 0.05). The Mode of triggering between the three groups had significant differences between the two groups (p < 0.05). In addition, the number of days from gonadotropin (Gn) initiation to antagonist addition were significantly different among the three groups (p < 0.05). In addition, total Gn doses,the number of oocytes retrieved, the number of Gn days, 2pronucleus (2PN) numbers, number of good quality embryos, and number of high risk OHSS (Ovarian Hyper-stimulation Syndrome), cases with OHSS occurrences were not significantly different among the three groups (p > 0.05). Moreover, the cycle and clinical pregnancy outcomes and the cumulative clinical pregnancy rate and the cumulative live birth rate were not significantly different among the three groups (p > 0.05). LH levels on the day of antagonist addition affected the number of good-quality embryos (B < 0, p < 0.05). However, LH levels on the day antagonist was added were not significantly correlated with basal LH levels (Pearson correlation coefficient = 0.259), the ROC curve was constructed for the logistic prediction model of the early onset LH peak, and the AUC value was 0.747, indicating that the logistic combined model we constructed had a good ability to predict the early onset LH peak.

CONCLUSION

Basal LH levels do not affect the pregnancy outcomes in PCOS patients after antagonist protocols. Besides, LH levels on the day of antagonist addition affect the number of good quality embryos for PCOS patients undergoing IVF /ICSI.

Polycystic ovarian syndrome and miscarriage in IVF: systematic revision of the literature and meta-analysis

PURPOSE

To evaluate the risk of miscarriage in IVF cycles in women with PCOS.

METHODS

Systematic review and meta-analysis. Systematic search of MEDLINE, EMBASE and Google Scholar. The language search was restricted to English, Spanish and French, from 2000 to 2019, with crosschecking of references from relevant articles. Inclusion criteria were: (1) IVF cycles (2) a group of patients with PCOS was considered separately, (3) the miscarriage rate was reported, (4) there was a control group, (5) definition of PCOS according the Rotterdam criteria. Exclusion criteria were been excluded from the meta-analysis: (1) publication prior to the year 2000, (2) animal studies, (3) reviews, (4) abstracts or conference papers, (5) letters, (6) case reports, (7) studies comparing different IVF techniques, (8) studies comparing groups with and without metformin or other treatments, (9) studies on induced abortions. Risk of bias was assessed by the Newcastle-Ottawa score (NOS). All the included studies had a low risk of bias (NOS scores ranging 7-8). The review protocol was registered in PROSPERO (CRD42020186713). Seventeen studies were included in the meta-analysis. There was a total of 10,472 pregnancies (2650 in PCOS and 7822 in controls) of which 1885 were miscarriages (682 in PCOS and 1203 in controls). We considered the miscarriage rate (MR), preclinical MR, early MR, and late MR.

RESULTS

In IVF pregnancies the risk of miscarriage was significantly increased when considering miscarriages in total (RR = 1.59; CI = 1.45-1.75), preclinical miscarriages (RR = 1.59; CI = 1.35-1.88), and early miscarriages (RR = 1.44; CI = 1.16-1.79). The increased miscarriage rate persisted in Chinese and Western populations when considered separately. The risk of miscarriage was increased in the subgroup of fresh transfers (RR = 1.21; CI = 1.06-1.39) as well as in the subgroup including either fresh or frozen transfers (RR = 1.95; CI = 1.72-2.22).

CONCLUSION

PCOS is linked to an increased MR in IVF pregnancies both of miscarriages in total, and to an increase in preclinical and early miscarriages.

PROSPERO NUMBER

CRD42020186713.

Elevated estradiol levels on hCG trigger day adversely effects on the clinical pregnancy rates of blastocyst embryo transfer but not cleavage-stage embryo transfer in fresh cycles: a retrospective cohort study

Background

Elevated estradiol (E₂) levels are an inevitable outcome of the controlled ovulation hyperstimulation. However, the effect of this change on pregnancy is still uncertain. Our study aimed to analyze the impact of increased serum E₂ at the day of human chorionic gonadotropin (hCG) administration on the clinical outcomes of women with fresh embryo transfer (ET) cycles.

Methods

This study included 3,009 fresh ET cycles from October 2015 to September 2021. Based on the stage of embryos transferred, these cycles were categorized into the cleavage group and blastocyst group. Both groups were then divided into four sets according to E₂ levels when hCG was administered: set 1 (E₂ ≤ 2,000 pg/ml), set 2 (E₂ = 2,001-3,000 pg/ml), set 3 (E₂ = 3,001-4,000 pg/ml), and set 4 (E₂ > 4,000 pg/ml). The primary outcome was the clinical pregnancy rate (CPR). Binary logistics regression analysis was established to explore the association between CPR and E2 levels. Specifically, the threshold effect of serum E2 on CPR was revealed using the two-piecewise linear regression analyses.

Results

The multivariate regression model in the cleavage group showed that patients' CPR in set 4 was 1.59 times higher than those in reference set 1, but the statistical difference was insignificant (P = 0.294). As for the blastocyst group, patients in set 4 had a lower CPR with adjusted ORs of 0.43 (P = 0.039) compared to patients in set 1. The inflection point for the blastocyst group was 39.7 pg/dl according to the results of the two-piecewise linear regression model. When E₂ levels were over the point, the CPR decreased by 17% with every 1 pg/dl increases in serum E₂ (adjusted OR = 0.83, 95% CI [0.72-0.96], P = 0.012).

Conclusions

Elevated E₂ levels (>39.7 pg/dl) on hCG trigger day were associated with decreased CPR in patients with fresh blastocyst ET. However, it had no similar effect on the CPR of patients with fresh cleavage-stage ET.

Clinical pregnancy rate for frozen embryo transfer with HRT: a randomized controlled pilot study comparing 1 week versus 2 weeks of oestradiol priming

RESEARCH QUESTION

Does a frozen-embryo transfer in an artificially-prepared endometrium (FET-HRT) cycle yield similar clinical pregnancy rate with 7 days of oestrogen priming compared to 14 days?

DESIGN

This is a single-centre, randomized, controlled, open-label pilot study. All FET-HRT cycles were performed in a tertiary centre between October 2018 and January 2021. Overall, 160 patients were randomized, with a 1:1 allocation, into two groups of 80 patients each: group A (7 days of E2 prior to P4 supplementation) and group B (14 days of E2 prior to P4 supplementation). Both groups received single blastocyst stage embryos on the 6th day of vaginal P4 administration. The primary outcome was the feasibility of such strategy assessed as clinical pregnancy rate, secondary outcomes were biochemical pregnancy rate, miscarriage rate, live birth rate and serum hormone levels on the day of FET. Chemical pregnancy was assessed by an hCG blood test 12 days after FET and clinical pregnancy was confirmed by transvaginal ultrasound at 7 weeks.

RESULTS

The analysis included 160 patients who were randomly assigned to either group A or group B on the seventh day of their FET-HRT cycle if the measured endometrial thickness was above 6.5 mm. Following screening failures and of drop-outs, 144 patients were finally included both in group A (75 patients) or group B (69 patients). Demographic characteristics for both groups were comparable. The biochemical pregnancy rate was 42.5% and 48.8% for group A and group B, respectively (p 0.526). Regarding the clinical pregnancy rate at 7 weeks, no statistical difference was observed (36.3% vs 46.3% for group A and group B, respectively, p = 0.261). The secondary outcomes of the study (biochemical pregnancy, miscarriage, and live birth rate) were comparable between the two groups for IIT analysis, as well as the P4 values on the day of FET.

CONCLUSIONS

In a frozen embryo transfer cycle, performed with artificial preparation of the endometrium, 7 versus 14 days of oestrogen priming are comparable, in terms of clinical pregnancy rate; the advantages of a seven-day protocol include the shorter time to pregnancy, reduced exposure to oestrogens, and more flexibility of scheduling and programming, and less probability to recruit a follicle and have a spontaneous LH surge. It is important to keep in mind that this study was designed as a pilot trial with a limited study population as such it was underpowered to determine the superiority of an intervention over another; larger-scale RCTs are warranted to confirm our preliminary results.

TRIAL REGISTRATION

Clinical trial number: NCT03930706.

Pregnancy Outcomes Associated with Ovarian Hyperstimulation Syndrome: A Retrospective Cohort Study of Infertile Women

Objective

To assess the relationship between ovarian hyperstimulation syndrome (OHSS) and adverse outcomes using population-based data in the United States. The hypothesis is that patients with OHSS were more likely to deliver preterm and more likely to have hypertensive disorders.

Methods

This retrospective cohort study identified 94 patients with OHSS and 183 matched referents in eight counties in Minnesota. Data were collected regarding pregnancy history, infertility treatment, and pregnancy outcomes. Using the Rochester Epidemiology Project, study subjects were identified from female patients, aged 18 to 49 years, who were diagnosed with infertility from January 2, 1995 to December 1, 2017, and had a pregnancy greater than 20 weeks' gestation. The primary outcome was preterm delivery or hypertensive disorder of pregnancy incidence in the OHSS group when compared with control patients. Chi-squared test, t test, and multivariate logistic models were used where appropriate.

Results

Patients with OHSS were more likely to deliver preterm (odds ratio, 2.14; 95% confidence interval, 1.26-3.65; P < 0.01), and their neonates were more likely to be small for gestational age (odds ratio, 4.78; 95% confidence interval, 1.61-14.19; P < 0.01). No significant differences between the groups were observed in any other outcome. Patients with OHSS are more likely to deliver preterm if they undergo fresh transfer compared with a freeze all and subsequent frozen transfer (odds ratio, 3.03, 95% confidence interval, 1.20-7.66, P = 0.02).

Conclusion

OHSS may lead to preterm birth and small-for-gestational-age neonates, which changes patient counseling and leads to arranging specialized obstetrical care for these patients with OHSS.

IVF/ICSI Outcomes After a Freeze-All Strategy: an Observational Cohort Study

In order to inform patients undergoing ART regarding their chances for motherhood, it seems useful to describe "freeze all" outcomes according to the different potential indications. The goal of this study was to examine the impact of a "freeze-all approach" on the cumulative live birth rate (cLBR) according to the indication. It is a cohort study including women who had undergone ovarian stimulation (OS) using an antagonist protocol with GnRH agonist triggering between 09.2016 and 09.2018 followed by a freeze-all cycle of blastocyst embryos. The ART outcomes were compared between the two main indications of the freeze-all strategy which were in our cohort: risk of ovarian hyperstimulation syndrome (OHSS) and endometriosis. The ART outcomes were also described for the others indications (inadequate endometrium and/or premature progesterone elevation at trigger day, two or more previous ART failures, and autoimmune disease and/or a high risk of thromboembolic disease (AI and/or TE risk)). In total, 658 women were included. The cLBR in the total population was 37.7% (248/658). The cLBR was significantly higher in the "OHSS risk" group (133/281, 47.3%) than in the "endometriosis" group (69/190, 36.3%) (p = 0.017). No significant differences were noted regarding perinatal outcomes, except a significantly higher risk of placenta praevia (PP) observed in the "endometriosis" group (10.1%) (p = 0.002). The "freeze-all approach" yielded good results in terms of the cLBR and especially in case of OHSS risk. These data should be taken into account when informing patients about the ART strategy and their chances of motherhood.

Comparison of perinatal outcomes and pregnancy complications between fresh embryo transfer and frozen embryo transfer in singleton pregnant women

OBJECTIVES

To compare perinatal outcomes and the incidence of pregnancy complications between fresh embryo transfer and frozen embryo transfer in singleton pregnant women.

METHODS

The clinical data of 3161 in vitro fertilization-embryo transfer cycles conducted in Center for Reproductive Medicine of the Third Affiliated Hospital of Sun Yat-sen University from October 2015 to May 2021 were retrospectively analyzed, among which 1009 cases were fresh embryo transfer (fresh embryo group) and 2152 cases were frozen embryo transfer (frozen embryo group). The baseline characteristics were compared between two groups, and logistic regression was used to analyze the effect of fresh embryo transfer and frozen embryo transfer on pregnancy outcome and complications.

RESULTS

Compared with the fresh embryo group, the frozen embryo group had an increased gestational age (P<0.01), increased birth weight (P<0.01), higher cesarean section rate (65.1% vs. 50.7%, AOR=1.791, 95%CI: 1.421-2.256, P<0.01), higher risk of large for gestational age infant (12.7% vs. 9.4%, AOR=1.487, 95%CI: 1.072-2.064, P<0.05) and macrosomia (5.4% vs. 3.2%, AOR=2.126, 95%CI: 1.262-3.582, P<0.01). The incidences of early abortion (18.5% vs. 16.2%, AOR=1.377, 95%CI: 1.099-1.725, P<0.01) and gestational hypertension (3.1% vs. 1.9%, AOR=1.862, 95%CI: 1.055-3.285, P<0.05) in the frozen embryo group were significantly higher than those in the fresh embryo group. Stratified analyses by stage of embryo transfer showed that during blastocyst transfer, the gestational weeks of delivery, birth weight and risk of cesarean section in frozen embryo group were significantly higher than those in fresh embryo group. During cleavage stage embryo transfer, frozen embryo transfer was associated with a higher risk of cesarean section, macrosomia, miscarriage and early miscarriage, and the birth weight of newborns was also significantly increased.

CONCLUSIONS

Compared with fresh embryo transfer, frozen embryo transfer is associated with a higher risk of abortion, early abortion, large for gestational age infant, macrosomia, cesarean section, and pregnancy induced hypertension. The birth weight of newborns after frozen embryo transfer is also significantly increased.

Effectiveness of progesterone rescue in women presenting low circulating progesterone levels around the day of embryo transfer: a systematic review and meta-analysis

IMPORTANCE

Over the last decade, frozen embryo transfer (FET) has been increasingly used in contemporary fertility units. Despite the rapid increase in FET, there is still insufficient evidence to recommend an optimized protocol for endometrial preparation especially in patients with lower progesterone (P4) levels. Previous studies have concluded that P4 levels <10 ng/mL are associated with poorer pregnancy outcomes than those reported with high levels of circulating P4.

OBJECTIVE

To identify whether rescue P4 dosing in patients with low P4 can salvage adverse outcomes associated with low P4 levels, resulting in outcomes comparable to patients with adequate progesterone.

DATA SOURCES

The study was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analyses guidelines and prospectively registered under the PROSPERO database (CRD42022357125). Six databases (Embase, MEDLINE, APA PsycInfo, Global Health, HMIC Health Management Information Consortium, and Google Scholar) and 2 additional sources were searched from inception to August 29, 2022.

STUDY SELECTION AND SYNTHESIS

Prospective and retrospective cohort studies, reporting the association between rescue progesterone and one or more pregnancy outcomes, were included. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS), while the quality of evidence by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. Summative and subgroup data as well as heterogeneity were generated by the Cochrane platform RevMan (V. 5.4).

MAIN OUTCOME MEASURE(S)

To compare ongoing pregnancy rate as primary outcome and clinical pregnancy rate, miscarriage rate, and live birth rate as secondary outcomes between patients with low (<10 ng/mL) receiving rescue progesterone vs. those with adequate levels of P4 (≥10 ng/mL).

RESULT(S)

Overall, 7 observational studies were included in the analysis, with a total of 5927 patients of median age 34 (interquartile range [IQR]: 31.55, 37.13). Overall, patient group comparison, namely those with low P4 that received a rescue dose and those with adequate P4 levels, did not yield significant differences for either the primary or secondary outcomes. For ongoing clinical pregnancy, patients with low P4 receiving the rescue dose vs. those with adequate P4 levels was odds ratio (OR) 0.98 (95% CI: 0.78, 1.24; P = .86, I²: 41%), whereas for miscarriage events, OR was 0.98 (95% CI: 0.81, 1.17; P = .80, I²: 0). Equally, for clinical pregnancy, OR was 0.91 (95% CI: 0.78, 1.06; P = .24; I²: 33%), and for live birth, OR was 0.92 (95% CI: 0.77, 1.09; P = .33; I²: 43%). Subgroup analysis on the basis or rescue administration route successfully explained summative heterogeneity.

CONCLUSION(S)

Rescue P4 dosing in patients with low P4 results in ongoing pregnancy rate, clinical pregnancy and live birth rates were comparable to those of patients with adequate P4 levels. However, robust randomized controlled trials assessing rescue treatment in women with low P4 are needed to confirm these findings. Rescue P4 in patients with low circulating P4 around embryo transfer day may result in reproductive outcomes comparable to those with adequate P4 levels.

STUDY REGISTRATION

CRD42022357125 (PROSPERO).

Obstetric and perinatal outcomes following frozen and fresh embryo transfer in patients with endometrial hyperplasia and carcinoma: a retrospective study in a high-volume reproductive center

BACKGROUND

There is ongoing debate regarding which embryo transfer procedure can achieve a higher live birth rate. Research has suggested that frozen ET might be beneficial for certain populations, such as hyper-responders. This study aimed to compare outcomes of pregnancies between frozen and fresh embryo transfer cycles in patients with endometrial hyperplasia and carcinoma.

METHODS

This retrospective cohort study was conducted at a high-volume reproductive center from January 2010 to January 2022. Patients who were diagnosed with endometrial hyperplasia with atypia and endometrial carcinoma were included. They all underwent in vitro fertilization after conservative treatment. The primary outcome was live birth after frozen and fresh embryo transfer cycles, and secondary outcomes included perinatal complications and other pregnancy outcomes.

RESULTS

Overall, 259 ET cycles (130 fresh and 129 frozen) were included. The rate of live births per embryo transfer cycle of the whole cohort was 20.8% (54/259), and no significant between-group difference was found after adjusting for potential confounding factors (23.8% vs. 17.8%; adjusted OR, 0.47; 95% CI, 0.21-1.06; p=0.068). Compared to fresh embryo transfer group, the incidence of total maternal complications in the frozen embryo transfer group was significantly higher (30.4% vs. 6.5%, p=0.019). Analyzing each complication as a separate entity, patients in the frozen embryo transfer group had a higher incidence of hypertensive disorders of pregnancy (p=0.028). Multiple logistic regression analysis showed that frozen embryo transfer was related with an increased occurrence of maternal complications (OR, 6.68, 95% CI, 1.01-44.19, p=0.040).

CONCLUSIONS

Among patients with endometrial hyperplasia and carcinoma, the rate of live births was comparable between both embryo transfer procedures, while frozen embryo transfer might be associated with a higher risk of maternal complications compared to that with fresh embryo transfer.

The impact of maternal ABO blood type on obstetric and perinatal outcomes after frozen embryo transfer

RESEARCH QUESTION

Does the maternal ABO blood type affect obstetric and perinatal outcomes following frozen embryo transfer (FET)?

DESIGN

A retrospective study was performed at a university-affiliated fertility centre, involving women with singleton and twin deliveries conceived by FET. Subjects were divided into four groups based on ABO blood type. The primary end-points were obstetric and perinatal outcomes.

RESULTS

A total of 20,981 women were involved, with 15,830 having singletons and 5151 delivering twins. In singleton pregnancies, women with blood group B had a slight but significantly increased risk of gestational diabetes mellitus compared to women with blood group O (adjusted odds ratio [aOR] 1.16; 95% confidence interval [CI] 1.01-1.34). Furthermore, singletons born to women with the B antigen (blood type B or AB) were more likely to be large for gestational age (LGA) and with macrosomia. In twin pregnancies, blood type AB was related to a decreased risk of hypertensive diseases of pregnancy (aOR 0.58; 95% CI 0.37-0.92), while blood type A was associated with a higher risk of placenta praevia (aOR 2.04; 95% CI 1.15-3.60). When compared with the O blood group, twins from the AB blood group had a lower risk of low birthweight (aOR 0.83; 95% CI 0.71-0.98) but a higher risk of LGA (aOR 1.26; 95% CI 1.05-1.52).

CONCLUSIONS

This study demonstrates that the ABO blood group may influence the obstetric and perinatal outcomes for both singletons and twins. These findings emphasize that patient characteristics could be, at least partly, responsible for adverse maternal and birth outcomes following IVF.

Impact of different endometrial preparation protocols before frozen embryo transfer on pregnancy outcomes: a review

The use of frozen embryo transfer cycles has exponentially increased in the last few years. Optimization of endometrial preparation protocols before frozen embryo transfer is mandatory to further improve pregnancy outcomes. This review will focus on the existing literature with regard to the different available endometrial preparation protocols and their impact on pregnancy outcomes. More specifically, we will focus on programmed, natural, and stimulated frozen embryo transfer cycles. The studies performed on this topic are generally of low quality, and only a few well-performed randomized controlled trials have been published. To date, no strong evidence is available to support the use of 1 preparation method over another in terms of pregnancy outcomes. However, robust data have shown a clearly protective effect of natural frozen embryo transfer cycles against long-term obstetric complications, mainly hypertensive disorders of pregnancy and large for gestational age infants. The introduction of individualized luteal phase support in different endometrial preparation protocols is actually gaining a lot of attention and requires further investigation.

Anti-Müllerian hormone in guiding the selection of a freeze-all versus a fresh embryo transfer strategy: a cohort study

PURPOSE

To explore an interaction effect between serum anti-Müllerian hormone (AMH) levels and the relative treatment effect of a freeze-all versus a fresh embryo transfer strategy on live birth.

METHODS

This was a retrospective cohort study investigating couples with infertility and eligible for both freeze-all and fresh embryo transfer between 2017 and 2019. Women with an absolute indication for a freeze-all strategy were excluded. Multivariable fractional polynomial interaction analysis within a logistic regression model was used to evaluate whether the treatment effect of a freeze-all versus a fresh transfer strategy varied at different AMH levels. Non-linear interactions were also considered. The primary outcome was the live birth after the first transfer.

RESULTS

A total of 13,503 women underwent a fresh embryo transfer and 2247 women underwent a freeze-all strategy. Live birth rates were slightly higher in the freeze-all group compared to those in the fresh embryo transfer group (35% vs 33%). There was a non-linear interaction between baseline serum AMH levels and the relative treatment effect of a freeze-all strategy versus a fresh transfer strategy on live birth (P = 0.0161). The benefit on live birth from a freeze-all embryo transfer strategy was greatest in women with a high serum level (> 7 ng/ml). The interaction remained valid when different imputation methods were used.

CONCLUSION

As serum AMH level increased, there was a nonlinear increase in relative treatment effect of a freeze-only transfer versus a fresh transfer strategy on live birth, and such an effect reaches its maximum in women with high AMH levels.

Cancer in children born after frozen-thawed embryo transfer: A cohort study

BACKGROUND

The aim was to investigate whether children born after assisted reproduction technology (ART), particularly after frozen-thawed embryo transfer (FET), are at higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception.

METHODS AND FINDINGS

We performed a registry-based cohort study using data from the 4 Nordic countries: Denmark, Finland, Norway, and Sweden. The study included 7,944,248 children, out of whom 171,774 children were born after use of ART (2.2%) and 7,772,474 children were born after spontaneous conception, representing all children born between the years 1994 to 2014 in Denmark, 1990 to 2014 in Finland, 1984 to 2015 in Norway, and 1985 to 2015 in Sweden. Rates for any cancer and specific cancer groups in children born after each conception method were determined by cross-linking national ART registry data with national cancer and health data registries and population registries. We used Cox proportional hazards models to estimate the risk of any cancer, with age as the time scale. After a mean follow-up of 9.9 and 12.5 years, the incidence rate (IR) of cancer before age 18 years was 19.3/100,000 person-years for children born after ART (329 cases) and 16.7/100,000 person-years for children born after spontaneous conception (16,184 cases). Adjusted hazard ratio (aHR) was 1.08, 95% confidence interval (CI) 0.96 to 1.21, p = 0.18. Adjustment was performed for sex, plurality, year of birth, country of birth, maternal age at birth, and parity. Children born after FET had a higher risk of cancer (48 cases; IR 30.1/100,000 person-years) compared to both fresh embryo transfer (IR 18.8/100,000 person-years), aHR 1.59, 95% CI 1.15 to 2.20, p = 0.005, and spontaneous conception, aHR 1.65, 95% CI 1.24 to 2.19, p = 0.001. Adjustment either for macrosomia, birth weight, or major birth defects attenuated the association marginally. Higher risks of epithelial tumors and melanoma after any assisted reproductive method and of leukemia after FET were observed. The main limitation of this study is the small number of children with cancer in the FET group.

CONCLUSIONS

Children born after FET had a higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception. The results should be interpreted cautiously based on the small number of children with cancer, but the findings raise concerns considering the increasing use of FET, in particular freeze-all strategies without clear medical indications.

TRIAL REGISTRATION

Trial registration number: ISRCTN 11780826.

Individual participant data meta-analysis of trials comparing frozen versus fresh embryo transfer strategy (INFORM): a protocol

INTRODUCTION

Existing randomised controlled trials (RCTs) comparing a freeze-all embryo transfer strategy and a fresh embryo transfer strategy have shown conflicting results. A freeze-all or a fresh transfer policy may be preferable for some couples undergoing in-vitro fertilisation (IVF), but it is unclear which couples would benefit most from each policy, how and under which protocols. Therefore, we plan a systematic review and individual participant data meta-analysis of RCTs comparing a freeze-all and a fresh transfer policy.

METHODS AND ANALYSIS

We will search electronic databases (Medline, Embase, PsycINFO and CENTRAL) and trial registries (ClinicalTrials.gov and the International Clinical Trials Registry Platform) from their inception to present to identify eligible RCTs. We will also check reference lists of relevant papers. The search was performed on 23 September 2020 and will be updated. We will include RCTs comparing a freeze-all embryo transfer strategy and a fresh embryo transfer strategy in couples undergoing IVF. The primary outcome will be live birth resulting from the first embryo transfer. All outcomes listed in the core outcome set for infertility research will be reported. We will invite the lead investigators of eligible trials to join the Individual participant data meta-analysis of trials comparing frozen versus fresh embryo transfer strategy (INFORM) collaboration and share the deidentified individual participant data (IPD) of their trials. We will harmonise the IPD and perform a two-stage meta-analysis and examine treatment-covariate interactions for important baseline characteristics.

ETHICS AND DISSEMINATION

The study ethics have been granted by the Monash University Human Research Ethics Committee (Project ID: 30391). The findings will be disseminated via presentations at international conferences and publication in peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42021296566.

Assisted Reproductive Technique and Abnormal Cord Insertion: A Systematic Review and Meta-Analysis

Abnormal cord insertion (ACI) is associated with adverse obstetric outcomes; however, the relationship between ACI and assisted reproductive technology (ART) has not been examined in a meta-analysis. This study examines the association between ACI and ART, and delivery outcomes of women with ACI. A systematic review was conducted, and 16 studies (1990–2021) met the inclusion criteria. In the unadjusted pooled analysis (n = 10), ART was correlated with a higher rate of velamentous cord insertion (VCI) (odds ratio (OR) 2.14, 95% confidence interval (CI) 1.64–2.79), marginal cord insertion (n = 6; OR 1.58, 95%CI 1.26–1.99), and vasa previa (n = 1; OR 10.96, 95%CI 2.94–40.89). Nevertheless, the VCI rate was similar among the different ART types (blastocyst versus cleavage-stage transfer and frozen versus fresh embryo transfer). Regarding the cesarean delivery (CD) rate, women with VCI were more likely to have elective (n = 3; OR 1.13, 95%CI 1.04–1.22) and emergent CD (n = 5; OR 1.93, 95%CI 1.82–2.03). In conclusion, ART may be correlated with an increased prevalence of ACI. However, most studies could not exclude confounding factors; thus, further studies are warranted to characterize ART as a risk factor for ACI. In women with ACI, elective and emergent CD rates are high.

Vaginal progesterone as luteal phase support in natural cycle frozen-thawed embryo transfer (ProFET): protocol for a multicentre, open-label, randomised controlled trial

INTRODUCTION

Vaginal progesterone supplementation is frequently given to patients receiving frozen embryo transfer (FET) in the natural cycle aiming to increase the chance of pregnancy and live birth. To date, only a few studies have investigated if progesterone supplementation is beneficial in these cycles and the level of evidence for progesterone supplementation is very low.

METHODS AND ANALYSIS

The ProFET trial is a multicentre, open-label, randomised controlled trial powered for this investigation, including 1800 women with regular menstrual cycles (24-35 days), aged 18-43 years planned for natural cycle-FET receiving a single blastocyst for transfer. Participants are randomised (1:1:1) to either luteal phase progesterone for 3 weeks, luteal phase progesterone for 7 weeks or no luteal phase progesterone. The participating study centres consist of 12 in vitro fertilisation-clinics in Sweden and 1 in Iceland. The primary outcome is to investigate if luteal phase support (LPS) by vaginal progesterone increases the chance of a live birth per randomised patient in a natural FET cycle compared with no LPS.

ETHICS AND DISSEMINATION

The trial was approved by the Swedish Ethical Review Authority (ID 2020-06774, 2021-02822 and 2022-01502-02) and the Swedish Medical Products Agency (ID nr 5.1-2020-102613). All participants are required to provide written informed consent. The outcome of this study will be disseminated to the public through broadcasts, newspapers and presentations at scientific congresses as well as publications in international scientific journals.

TRIAL REGISTRATION NUMBER

NCT04725864.

Comparison of perinatal outcomes after frozen or fresh embryo transfer: separate analyses of singleton, twin, and sibling live births from a linked national in vitro fertilization registry

OBJECTIVE

To determine whether perinatal outcomes following frozen vs. fresh embryo transfer (ET) differ within singletons, within sets of twins, and between siblings.

DESIGN

Population-based retrospective cohort study.

SETTING

Academic Medical School PATIENT(S): 200,075 live births in 151,561 women who underwent in vitro fertilization with frozen or fresh ET between 1992 and 2017.

MAIN OUTCOME MEASURE(S)

Gestational age at birth, birthweight, congenital anomaly, and healthy baby (≥37 weeks of gestation, birthweight 2,500-4,000 g, no congenital malformations).

RESULT(S)

There were 200,075 live births in 151,561 women including 132,679 singletons, 33,698 sets of twins, and 5,723 pairs of singleton siblings. In singletons, frozen ET was associated with a lower risk of very preterm birth (adjusted relative risk [aRR], 0.83; 95% confidence interval [CI], 0.73, 0.94), preterm birth (aRR, 0.93; 95% CI, 0.88, 0.97), low birthweight (<2,500 g) (aRR, 0.72; 95% CI, 0.68, 0.77), small for gestational age (aRR, 0.66; 95% CI, 0.62, 0.70) and congenital anomaly (aRR, 0.85; 95% CI, 0.78, 0.94), but higher risk of high birthweight (>4,000 g) (aRR, 1.64; 95% CI, 1.58, 1.72) and large for gestational age (aRR, 1.62; 95% CI, 1.55, 1.70) in comparison with fresh ET. In twins, frozen ET was associated with lower risk of very preterm birth (aRR, 0.84; 95% CI, 0.73, 0.97), and low birthweight (aRR, 0.72; 95% CI, 0.68, 0.77), but with a higher chance of a healthy baby (aRR, 1.11; 95% CI, 1.06, 1.16) compared to fresh ET. Singletons conceived following frozen ET had a lower risk of low birthweight (aRR, 0.56; 95% CI, 0.44, 0.74) and being small for gestational age (aRR, 0.54; 95% CI, 0.42, 0.68) than a singleton sibling born after a fresh ET. Frozen ET also was associated with higher risk of high birthweight (aRR, 1.85; 95% CI, 1.54, 2.24) and being large for gestational age (aRR, 1.81; 95% CI, 1.50, 2.20), and also were less likely to be preterm (aRR, 0.81; 95% CI, 0.67, 0.99).

CONCLUSION(S)

Our key finding is that singletons born following a frozen ET are less likely to be small for gestational age than a singleton sibling born following fresh ET but are more likely to be large for gestational age.

Predicting the probability of a live birth after a freeze-all based in vitro fertilization-embryo transfer (IVF-ET) treatment strategy

BACKGROUND

The predictors for live birth rate (LBR) following one episode of in vitro fertilization (IVF) cycle for patients using a "freeze-all" strategy are not entirely clear.

METHODS

A retrospective cohort study utilizing a prediction model was developed to assess the relationship to the LBR. Women undergoing IVF with a freeze-all strategy were screened. Univariate models were first fitted for female age at oocytes retrieval/frozen-thawed embryo transfer (FET), body mass index (BMI), duration and etiology of infertility, previous IVF failures, total dose and duration of gonadotrophin, ovarian sensitivity index (OSI), number of oocytes collected, method of fertilization, number of embryos created, number and stage of embryos frozen, type and number of FET cycles, endometrial thickness (EMT)/pattern, hormone level on transplantation day, storage duration, number of embryos thawed and damaged thawed embryos, number and stage of embryos transferred and number of different quality embryos transferred. Variables with P<0.05 in the univariate model were selected for further analysis of the final multivariate discrete-time logistic regression model.

RESULTS

A total of 7,602 women undergoing one ovarian stimulation resulted in 9,964 FETs, of whom 3,066 (40.33%) had a live-birth after their first FET and 3,929 (51.68%) after total FETs. The EMT and woman's age at oocyte retrieval were the most important predictors. In the first FET, the LBR of women with an EMT ≤8 mm [27.40%; 95% confidence interval (CI): (21.60-33.81%)] was significantly lower than that of women with EMT between 9 and 11 mm [36.51%; 95% CI: (34.25-38.81%)] and thicker than 12 mm [44.23%; 95% CI: (42.22-46.25%)] (P<0.05). The optimistic and conservative cumulative LBRs of women younger than 31 years [87.5%; 95% CI: (86.32-88.61%) and 63.04%; 95% CI: (61.36-64.69%)] were significantly decreased in women aged 31-35, 36-40 and >40 (P<0.001).

CONCLUSIONS

Our study provides an effective prediction model for a woman's chance of having a baby after a "freeze-all" policy. The use of EMT and female age as tools to identify LBR are shown to be justified, and repeated FETs cannot reverse the age-dependent decline in fertility.

Effect of post‐warming culture time on the live birth rate after frozen embryo transfer

Purpose

Methods

Results

Conclusions

Should any use of artificial cycle regimen for frozen-thawed embryo transfer in women capable of ovulation be abandoned: yes, but what's next for FET cycle practice and research?

Over the past decade, the use of frozen-thawed embryo transfer (FET) treatment cycles has increased substantially. The artificial ('programmed') cycle regimen, which suppresses ovulation, is widely used for that purpose, also in ovulatory women or women capable of ovulation, under the assumption of equivalent efficacy in terms of pregnancy achievement as compared to a natural cycle or modified natural cycle. The advantage of the artificial cycle is the easy alignment of the time point of thawing and transferring embryos with organizational necessities of the IVF laboratory, the treating doctors and the patient. However, recent data indicate that pregnancy establishment under absence of a corpus luteum as a consequence of anovulation may cause relevant maternal and fetal risks. Herein, we argue that randomized controlled trials (RCTs) are not needed to aid in the clinical decision for or against routine artificial cycle regimen use in ovulatory women. We also argue that RCTs are unlikely to answer the most burning questions of interest in that context, mostly because of lack of power and precision in detecting rare but decisive adverse outcomes (e.g. pre-eclampsia risk or long-term neonatal health outcomes). We pinpoint that, instead, large-scale observational data are better suited for that purpose. Eventually, we propose that the existing understanding and evidence is sufficient already to discourage the use of artificial cycle regimens for FET in ovulatory women or women capable of ovulation, as these may cause a strong deviation from physiology, thereby putting patient and fetus at avoidable health risk, without any apparent health benefit.

Endometriosis and Infertility: A Long-Life Approach to Preserve Reproductive Integrity

Laparoscopic surgery was originally considered the gold standard in the treatment of endometriosis-related infertility. Assisted reproductive technology (ART) was indicated as second-line treatment or in the case of male factor. The combined approach of surgery followed by ART proved to offer higher chances of pregnancy in infertile women with endometriosis. However, it was highlighted how pelvic surgery for endometriosis, especially in cases of ovarian endometriomas, could cause iatrogenic damage due to ovarian reserve loss, adhesion formation (scarring), and ischemic damage. Furthermore, in the last few years, the trend to delay the first childbirth, recent technological advances in ultrasound diagnosis, and technological progress in clinical and laboratory aspects of ART have certainly influenced the approach to infertility and endometriosis with, ART assuming a more relevant role. Management of endometriosis should take into account that the disease is chronic and involves the reproductive system. Consequently, treatment and counselling should aim to preserve the chances of pregnancy for the patient, even if it is not associated with infertility. This review will analyse the evolution of the management of infertility associated with endometriosis and propose an algorithm for treatment decision-making based on the most recent acquisitions.

Algorithm-based individualization methodology of the starting gonadotropin dose in IVF/ICSI and the freeze-all strategy prevent OHSS equally in normal responders: a systematic review and network meta-analysis of the evidence

PURPOSE

Ovarian hyperstimulation syndrome (OHSS) represents a rare but dangerous condition associated with controlled ovarian stimulation (COS) in IVF/ICSI. Over the last decades, many strategies have been introduced into clinical practice with the objective of preventing this potentially life-threatening condition. Among these, the freeze-all policy has gained great popularity, thanks to improvements in vitrification. Nevertheless, not all clinics have adequate skills in vitrification procedures and patients may be dissatisfied with a longer time to pregnancy.

METHODS

This study is a systematic review and network meta-analysis of randomized controlled trials comparing different strategies of ovarian stimulation in IVF/ICSI cycles (freeze-all policy, algorithm-based individualization of the starting dose, experience-based individualization of the starting dose, standard dose) in terms of reduction of OHSS, in normal responders.

RESULTS

The results indicate that only the algorithm-based individualization of the starting gonadotropin dose reduces OHSS similarly to the freeze-all strategy.

CONCLUSION

Albeit in the era of the freeze-all policy, the personalization of the starting gonadotropin dose obtained by the use of algorithms should be pursued as a valid and safe option for IVF.

Transfer of thawed frozen embryo versus fresh embryo to improve the healthy baby rate in women undergoing IVF: the E-Freeze RCT

BACKGROUND

Freezing all embryos, followed by thawing and transferring them into the uterine cavity at a later stage (freeze-all), instead of fresh-embryo transfer may lead to improved pregnancy rates and fewer complications during in vitro fertilisation and pregnancies resulting from it.

OBJECTIVE

We aimed to evaluate if a policy of freeze-all results in a higher healthy baby rate than the current policy of transferring fresh embryos.

DESIGN

This was a pragmatic, multicentre, two-arm, parallel-group, non-blinded, randomised controlled trial.

SETTING

Eighteen in vitro fertilisation clinics across the UK participated from February 2016 to April 2019.

PARTICIPANTS

Couples undergoing their first, second or third cycle of in vitro fertilisation treatment in which the female partner was aged < 42 years.

INTERVENTIONS

If at least three good-quality embryos were present on day 3 of embryo development, couples were randomly allocated to either freeze-all (intervention) or fresh-embryo transfer (control).

OUTCOMES

The primary outcome was a healthy baby, defined as a live, singleton baby born at term, with an appropriate weight for their gestation. Secondary outcomes included ovarian hyperstimulation, live birth and clinical pregnancy rates, complications of pregnancy and childbirth, health economic outcome, and State-Trait Anxiety Inventory scores.

RESULTS

A total of 1578 couples were consented and 619 couples were randomised. Most non-randomisations were because of the non-availability of at least three good-quality embryos (n = 476). Of the couples randomised, 117 (19%) did not adhere to the allocated intervention. The rate of non-adherence was higher in the freeze-all arm, with the leading reason being patient choice. The intention-to-treat analysis showed a healthy baby rate of 20.3% in the freeze-all arm and 24.4% in the fresh-embryo transfer arm (risk ratio 0.84, 95% confidence interval 0.62 to 1.15). Similar results were obtained using complier-average causal effect analysis (risk ratio 0.77, 95% confidence interval 0.44 to 1.10), per-protocol analysis (risk ratio 0.87, 95% confidence interval 0.59 to 1.26) and as-treated analysis (risk ratio 0.91, 95% confidence interval 0.64 to 1.29). The risk of ovarian hyperstimulation was 3.6% in the freeze-all arm and 8.1% in the fresh-embryo transfer arm (risk ratio 0.44, 99% confidence interval 0.15 to 1.30). There were no statistically significant differences between the freeze-all and the fresh-embryo transfer arms in the live birth rates (28.3% vs. 34.3%; risk ratio 0.83, 99% confidence interval 0.65 to 1.06) and clinical pregnancy rates (33.9% vs. 40.1%; risk ratio 0.85, 99% confidence interval 0.65 to 1.11). There was no statistically significant difference in anxiety scores for male participants (mean difference 0.1, 99% confidence interval -2.4 to 2.6) and female participants (mean difference 0.0, 99% confidence interval -2.2 to 2.2) between the arms. The economic analysis showed that freeze-all had a low probability of being cost-effective in terms of the incremental cost per healthy baby and incremental cost per live birth.

LIMITATIONS

We were unable to reach the original planned sample size of 1086 and the rate of non-adherence to the allocated intervention was much higher than expected.

CONCLUSION

When efficacy, safety and costs are considered, freeze-all is not better than fresh-embryo transfer.

TRIAL REGISTRATION

This trial is registered as ISRCTN61225414.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 25. See the NIHR Journals Library website for further project information.

Ovarian Stimulation in Assisted Reproductive Technology Cycles for Varied Patient Profiles: An Indian Perspective

Controlled ovarian stimulation has been an integral part of in vitro fertilisation (IVF) treatment cycles. Availability of different gonadotropins for ovarian stimulation and gonadotropin releasing hormone (GnRH) analogues for prevention of premature rise of leutinising hormone during follicular phase offer an opportunity to utilise them for a successful outcome in women with different subsets of ovarian response. Further, use of GnRH agonist as an alternative for human chorionic gonadotropin improves safety of ovarian stimulation in hyper-responders. Mild ovarian stimulation protocols have emerged as an alternative to conventional protocols in the recent years. Individualisation plays an important role in improving safety of IVF in hyper-responders while efforts continue to improve efficacy in poor responders. Some of the follicular and peri-ovulatory phase interventions may be associated with negative impact on the luteal phase and segmentalisation of the treatment with frozen embryo transfer may be an effective strategy in such a clinical scenario. This narrative review looks at the available evidence on various aspects of ovarian stimulation strategies and their consequences. In addition, it provides a concise summary of the evidence that has emerged from India on various aspects of ovarian stimulation.

Elective freezing of embryos versus fresh embryo transfer in IVF: a multicentre randomized controlled trial in the UK (E-Freeze)

STUDY QUESTION

Does a policy of elective freezing of embryos, followed by frozen embryo transfer result in a higher healthy baby rate, after first embryo transfer, when compared with the current policy of transferring fresh embryos?

SUMMARY ANSWER

This study, although limited by sample size, provides no evidence to support the adoption of a routine policy of elective freeze in preference to fresh embryo transfer in order to improve IVF effectiveness in obtaining a healthy baby.

WHAT IS KNOWN ALREADY

The policy of freezing all embryos followed by frozen embryo transfer is associated with a higher live birth rate for high responders but a similar/lower live birth after first embryo transfer and cumulative live birth rate for normal responders. Frozen embryo transfer is associated with a lower risk of ovarian hyperstimulation syndrome (OHSS), preterm delivery and low birthweight babies but a higher risk of large babies and pre-eclampsia. There is also uncertainty about long-term outcomes, hence shifting to a policy of elective freezing for all remains controversial given the delay in treatment and extra costs involved in freezing all embryos.

STUDY DESIGN, SIZE, DURATION

A pragmatic two-arm parallel randomized controlled trial (E-Freeze) was conducted across 18 clinics in the UK from 2016 to 2019. A total of 619 couples were randomized (309 to elective freeze/310 to fresh). The primary outcome was a healthy baby after first embryo transfer (term, singleton live birth with appropriate weight for gestation); secondary outcomes included OHSS, live birth, clinical pregnancy, pregnancy complications and cost-effectiveness.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Couples undergoing their first, second or third cycle of IVF/ICSI treatment, with at least three good quality embryos on Day 3 where the female partner was ≥18 and <42 years of age were eligible. Those using donor gametes, undergoing preimplantation genetic testing or planning to freeze all their embryos were excluded. IVF/ICSI treatment was carried out according to local protocols. Women were followed up for pregnancy outcome after first embryo transfer following randomization.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 619 couples randomized, 307 and 309 couples in the elective freeze and fresh transfer arms, respectively, were included in the primary analysis. There was no evidence of a statistically significant difference in outcomes in the elective freeze group compared to the fresh embryo transfer group: healthy baby rate {20.3% (62/307) versus 24.4% (75/309); risk ratio (RR), 95% CI: 0.84, 0.62 to 1.15}; OHSS (3.6% versus 8.1%; RR, 99% CI: 0.44, 0.15 to 1.30); live birth rate (28.3% versus 34.3%; RR, 99% CI 0.83, 0.65 to 1.06); and miscarriage (14.3% versus 12.9%; RR, 99% CI: 1.09, 0.72 to 1.66). Adherence to allocation was poor in the elective freeze group. The elective freeze approach was more costly and was unlikely to be cost-effective in a UK National Health Service context.

LIMITATIONS, REASONS FOR CAUTION

We have only reported on first embryo transfer after randomization; data on the cumulative live birth rate requires further follow-up. Planned target sample size was not obtained and the non-adherence to allocation rate was high among couples in the elective freeze arm owing to patient preference for fresh embryo transfer, but an analysis which took non-adherence into account showed similar results.

WIDER IMPLICATIONS OF THE FINDINGS

Results from the E-Freeze trial do not lend support to the policy of electively freezing all for everyone, taking both efficacy, safety and costs considerations into account. This method should only be adopted if there is a definite clinical indication.

STUDY FUNDING/COMPETING INTEREST(S)

NIHR Health Technology Assessment programme (13/115/82). This research was funded by the National Institute for Health Research (NIHR) (NIHR unique award identifier) using UK aid from the UK Government to support global health research. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR or the UK Department of Health and Social Care. J.L.B., C.C., E.J., P.H., J.J.K., L.L. and G.S. report receipt of funding from NIHR, during the conduct of the study. J.L.B., E.J., P.H., K.S. and L.L. report receipt of funding from NIHR, during the conduct of the study and outside the submitted work. A.M. reports grants from NIHR personal fees from Merck Serono, personal fees for lectures from Merck Serono, Ferring and Cooks outside the submitted work; travel/meeting support from Ferring and Pharmasure and participation in a Ferring advisory board. S.B. reports receipt of royalties and licenses from Cambridge University Press, a board membership role for NHS Grampian and other financial or non-financial interests related to his roles as Editor-in-Chief of Human Reproduction Open and Editor and Contributing Author of Reproductive Medicine for the MRCOG, Cambridge University Press. D.B. reports grants from NIHR, during the conduct of the study; grants from European Commission, grants from Diabetes UK, grants from NIHR, grants from ESHRE, grants from MRC, outside the submitted work. Y.C. reports speaker fees from Merck Serono, and advisory board role for Merck Serono and shares in Complete Fertility. P.H. reports membership of the HTA Commissioning Committee. E.J. reports membership of the NHS England and NIHR Partnership Programme, membership of five Data Monitoring Committees (Chair of two), membership of six Trial Steering Committees (Chair of four), membership of the Northern Ireland Clinical Trials Unit Advisory Group and Chair of the board of Oxford Brain Health Clinical Trials Unit. R.M. reports consulting fees from Gedeon Richter, honorarium from Merck, support fees for attendance at educational events and conferences for Merck, Ferring, Bessins and Gedeon Richter, payments for participation on a Merck Safety or Advisory Board, Chair of the British Fertility Society and payments for an advisory role to the Human Fertilisation and Embryology Authority. G.S. reports travel and accommodation fees for attendance at a health economic advisory board from Merck KGaA, Darmstadt, Germany. N.R.-F. reports shares in Nurture Fertility. Other authors' competing interests: none declared.

TRIAL REGISTRATION NUMBER

ISRCTN: 61225414.

TRIAL REGISTRATION DATE

29 December 2015.

DATE OF FIRST PATIENT’S ENROLMENT

16 February 2016.

Cumulative live birth rate per oocyte aspiration in artificial reproduction technology: A retrospective observational study of the association between maternal age and the number of oocytes retrieved in an Indian population

Background:

The association between cumulative live birth rate (CLBR) and oocyte aspiration in the context of maternal age is not well understood in the Indian population.

Aims:

To find the relationship between CLBR and a single oocyte aspiration.

Settings and Design:

This is a retrospective study analysing the data of 1989 women who underwent in vitro fertilisation (IVF) between January 2015 and December 2019, at Gunasheela Surgical and Maternity Hospital, India.

Materials and Methods:

Participants were divided into two groups based on age: ≤35 (group I, n = 1665) and >35 (Group II, n = 324). CLBR per single oocyte aspiration in fresh and subsequent three frozen embryo transfer cycles was estimated.

Statistical Analysis Used:

Logistic regression analysis was used to show the likelihood of pregnancy rate, and CLBR per aspiration after treatment was represented as odd's ratios (OR) with 95% confidence intervals.

Results:

Maximal CLBR for Groups I and II was 81.25% with >25 oocytes and 75% with 16–20 oocytes, respectively. In the fresh ET cycle, maximal pregnancy and live birth rates were observed in 6–10 oocytes for Group I (54% and 41%) and in 16–20 oocytes for Group II (75% and 75%). The ORs for pregnancy rate (P = 0.01) and CLBR (P = 0.007) increased with an increase in the number of oocytes retrieved. The ORs for pregnancy rate and CLBR for Group II were 0.68 (P = 0.002) and 0.58 (P = 0.00002), respectively as compared to Group I. Optimal oocytes required to achieve positive IVF outcomes in fresh/frozen ET cycles were low in Group I (6–10 oocytes), but higher in Group II (16–20 oocytes).

Conclusion:

Robust positive relationship was observed between the number of oocytes retrieved and CLBR in women of both age groups.

Pretreatment with a GnRH agonist and hormone replacement treatment protocol could not improve live birth rate for PCOS women undergoing frozen-thawed embryo transfer cycles

BACKGROUND

The ideal protocols of endometrial preparation for polycystic ovary syndrome (PCOS) patients are lacking and need further declaration. Our objective was to compare the clinical outcomes of frozen-thawed embryo transfer (FET) with and without pretreatment gonadotropin-releasing hormone agonist (GnRHa) in PCOS patients.

METHODS

In this retrospective cohort study, we used propensity score matching (PSM) to compare the live birth rate between patients who underwent FET with hormone replacement treatment (HRT) and patients with GnRHa pretreatment (GnRHa + HRT). Patients using GnRHa + HRT (n = 514) were matched with 514 patients using HRT.

RESULTS

The live birth rate was higher in the GnRHa + HRT group compared with the HRT group with no significant difference (60.12% vs 56.03%, p = 0.073). The clinical pregnancy rate (75.29% vs 70.62%), miscarriage rate (14.20% vs 13.81%) and ectopic pregnancy rate (0.39% vs 0.19%) were similar between the two groups. The preterm birth rate in GnRHa + HRT was higher than HRT (20.23% vs 13.04%). No difference was found in live birth between GnRHa +HRT and HRT before adjusting for covariates (crude OR 1.22, 95%CI, 0.99-1.51, p = 0.062) and after PSM (OR 1.47, 95%CI, 0.99-2.83, p = 0.068). In addition, there is a marginally difference after adjusting for covariates (aOR 1.56, 95%CI, 1.001-2.41, p = 0.048), this finding with p-value close to 0.05 represent insufficient empirical evidence. Similar results were obtained after propensity score matching in the entire cohort.

CONCLUSIONS

GnRHa pretreatment could not improve the live birth rate in women with PCOS.

Assisted reproductive technology in Japan: A summary report for 2019 by the Ethics Committee of the Japan Society of Obstetrics and Gynecology

Purpose

The Japan Society of Obstetrics and Gynecology records online annual cycle‐based information for assisted reproductive technology (ART). This report presents the characteristics and treatment outcomes of ART cycles registered during 2019.

Methods

The Japanese ART registry includes cycle‐specific information from 619 participating facilities, including treatment and pregnancy outcomes. Descriptive analyses were conducted for cycles registered during 2019.

Results

In 2019, 458 101 treatment cycles and 60 598 neonates were reported, both of which increased from 2018. The number of fresh cycles, including in vitro fertilization and intracytoplasmic sperm injection, decreased, while frozen‐thawed embryo transfer (ET) cycles increased. The mean maternal age was 37.9 years (standard deviation ± 4.7). Of 239 348 oocyte retrievals, 123 690 (51.7%) involved freeze‐all‐embryos cycles; fresh ET was performed in 41 831 cycles (a decreasing trend since 2015). In 2019, there were 211 597 frozen‐thawed ET cycles, resulting in 74 882 pregnancies and 54 168 neonates born. Single ET was performed in 82.6% of fresh transfers and 85.1% of frozen‐thawed cycles, with singleton live birth rates of 97.3% for both.

Conclusions

The number of fresh cycles decreased but frozen cycles increased in 2019. Single ET was performed in >80% of cases, and the proportion of babies born from frozen‐thawed ET increased.

Assessing couples' preferences for fresh or frozen embryo transfer: a discrete choice experiment

STUDY QUESTION

What are couples' preferences for fresh embryo transfer versus freezing of all embryos followed by frozen embryo transfer and the associated clinical outcomes that may differentiate them?

SUMMARY ANSWER

Couples' preferences are driven by anticipated chances of live birth, miscarriage, neonatal complications, and costs but not by the differences in the treatment process (including delay of embryo transfer linked to frozen embryo transfer and risk of ovarian hyperstimulation syndrome (OHSS) associated with fresh embryo transfer).

WHAT IS KNOWN ALREADY

A policy of freezing all embryos followed by transfer of frozen embryos results in livebirth rates which are similar to or higher than those following the transfer of fresh embryos while reducing the risk of OHSS and small for gestational age babies: it can, however, increase the risk of pre-eclampsia and large for gestational age offspring. Hence, the controversy continues over whether to do fresh embryo transfer or freeze all embryos followed by frozen embryo transfer.

STUDY DESIGN, SIZE, DURATION

We used a discrete choice experiment (DCE) technique to survey infertile couples between August 2018 and January 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We asked IVF naïve couples attending a tertiary referral centre to independently complete a questionnaire with nine hypothetical choice tasks between fresh and frozen embryo transfer. The alternatives varied across the choice occurrences on several attributes including efficacy (live birth rate), safety (miscarriage rate, neonatal complication rate), and cost of treatment. We assumed that a freeze-all strategy prolonged treatment but reduced the risk of OHSS. An error components mixed logit model was used to estimate the relative value (utility) that couples placed on the alternative treatment approaches and the attributes used to describe them. Willingness to pay and marginal rates of substitution between the non-cost attributes were calculated. A total of 360 individual questionnaires were given to 180 couples who fulfilled the inclusion criteria, of which 212 were completed and returned Our study population included 3 same sex couples (2 females and 1 male) and 101 heterosexual couples. Four questionnaires were filled by one partner only. The response rate was 58.8%.

MAIN RESULTS AND THE ROLE OF CHANCE

Couples preferred both fresh and frozen embryo transfer (odds ratio 27.93 and 28.06, respectively) compared with no IVF treatment, with no strong preference for fresh over frozen. Couples strongly preferred any IVF technique that offered an increase in live birth rates by 5% (P = 0.006) and 15% (P < 0.0001), reduced miscarriage by 18% (P < 0.0001) and diminished neonatal complications by 10% (P < 0.0001). Respondents were willing to pay an additional £2451 (95% CI 604 - 4299) and £761 (95% CI 5056-9265) for a 5 and 15% increase in the chance of live birth, respectively, regardless of whether this involved fresh or frozen embryos. They required compensation of £5230 (95% CI 3320 - 7141) and £13 245 (95% CI 10 110-16 380) to accept a 10 and 25% increase in the risk of neonatal complications, respectively (P < 0.001). Results indicated that couples would be willing to accept a 1.26% (95% CI 1.001 - 1.706) reduction in the live birth rate for a 1% reduction in the risk of neonatal complications per live birth. Older couples appeared to place less emphasis on the risk of neonatal complications than younger couples.

LIMITATIONS, REASONS FOR CAUTION

DCEs can elicit intentions which may not reflect actual behaviour. The external validity of this study is limited by the fact that it was conducted in a single centre with generous public funding for IVF. We cannot rule out the potential for selection or responder bias.

WIDER IMPLICATIONS OF THE FINDINGS

If a strategy of freeze all was to be implemented it would appear to be acceptable to patients, if either success rates can be improved or neonatal complications reduced. Live birth rates, neonatal complication rates, miscarriage rates, and cost are more likely to drive their preferences than a slight delay in the treatment process. The results of this study have important implications for future economic evaluations of IVF, as they suggest that the appropriate balance needs to be struck between success and safety. A holistic approach incorporating patient preferences for expected clinical outcomes and risks should be taken into consideration for individualized care.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was sought for this study. A.M. is the chief investigator of the randomized controlled trial 'Freeze all'. S.B. is an Editor in Chief of Human Reproduction Open. The other co-authors have no conflicts of interest to declare. Graham Scotland reports non-financial support from Merck KGaA, Darmstadt, Germany, outside the submitted work.

TRIAL REGISTRATION NUMBER

N/A.

Progesterone and estrogen levels are associated with live birth rates following artificial cycle frozen embryo transfers

PURPOSE

Does an association exist between serum progesterone and estradiol levels and live birth rates in artificial cycle frozen embryo transfer (AC-FET)?

METHODS

Retrospective cohort study was based on prospectively collected data at a university-affiliated fertility center. Included were all cycles using an artificial endometrial preparation with estradiol hemihydrate (Estrofem, 2 mg/8 h) and vaginal progesterone (Endometrin 100 mg/8 h), autologous oocytes, and cleavage stage embryo transfers. Serum progesterone and estradiol levels were measured 14 days after FET. A total of 921 cycles in 568 patients from to December 2010 to June 2019 were investigated. Live birth was the primary outcome measure.

RESULTS

Significant association was found between live birth and progesterone as well as estradiol levels (progesterone 14.65 vs 11.62 ng/ml, p = 0.001; estradiol 355.12 vs 287.67 pg/ml, p = 0.001). A significant difference in live birth rate was found below and above the median progesterone level (10.9 ng/ml, p = 0.007). Lower estradiol level was significantly associated with lower live birth rate (< 188.2 pg/ml 8.3%, > 263.1 pg/ml 16%, p = 0.02).

CONCLUSIONS

Serum progesterone and estradiol levels impact live birth rate in AC-FET.

Immediate versus delayed frozen embryo transfer in women following a failed IVF-ET attempt: a multicenter randomized controlled trial

BACKGROUND

The optimal time at which to perform a frozen-thawed embryo transfer (FET) following a failed in-vitro fertilization-embryo transfer (IVF-ET) attempt remains elusive to most reproductive experts. Physicians often delay the introduction of FET due to concerns related to potential residual effects of ovarian hyperstimulation which may interfere with the regular menstrual cycle. Moreover, given that most of the published studies on the topic are retrospective and have inconsistent findings, it is crucial to develop evidence-based randomized control guides for clinical practice. Therefore, this well-designed randomized controlled trial (RCT) was conducted to determine whether it is necessary to delay FET for at least one menstrual cycle after the failure of fresh embryo transfer.

METHODS

Infertile women eligible for IVF-ET were invited to participate in this multicenter, randomized, non-inferiority, parallel-group, unblinded, controlled trial at the academic fertility centers of four public hospitals in Chinese Mainland. Infertile women scheduled to receive their first FET cycle after a failed IVF-ET attempt were randomly assigned to either (a) the immediate FET group in which FET was performed in the first menstrual cycle following the failed IVF-ET cycle (n = 366) or (b) the delayed FET group in which FET was performed in the second or subsequent menstrual cycle following the failed IVF-ET cycle (n = 366). All FET cycles were performed during hormone replacement cycles for endometrial preparation. The primary outcome was the ongoing pregnancy, defined as a detectable fetal heart beat beyond twelve weeks of gestation. Secondary outcomes were other pregnancy-related outcomes, maternal and neonatal complications. Analysis was performed by both intention-to-treat and per-protocol principles.

RESULTS

A total of 646 FETs were completed. The frequency of moderate to severe depression and high stress level prior to FET in delayed FET group were significantly higher than that in immediate FET group (10.6% vs 6.1%, p = 0.039; 30.3% vs 22.4%, p = 0.022, respectively). Immediate FET resulted in a higher frequency of clinical pregnancy than did delayed FET (41.7% vs 34.1%), for a relative risk (RR) of 1.23 (95% confidence interval [CI], 1.00-1.50; p = 0.045). Women who underwent immediate FET also had a lower frequency of biochemical pregnancy loss (11.7% vs. 30.6%), with a RR of 0.28 (95% CI 0.23-0.63, p < 0.001), and a higher frequency of embryo implantation (25.2% vs. 20.2%), with a RR of 1.25 (95% CI 1.01-1.53; p = 0.038). Although the ongoing pregnancy and live birth rates did not differ significantly between the immediate FET and delayed FET groups (37.1% vs 30.3%, RR 1.22, 95% CI 0.99-1.52, p = 0.067; 36.5% vs 30.0%, RR 1.22, 95% CI 0.98-1.52, p = 0.079, respectively), a multivariate logistic regression analysis adjusted for potential confounders such as depression and stress levels revealed that the immediate FET group had a significantly higher ongoing pregnancy and live birth rates than the delayed FET group (odds ratio 0.68, 95% CI 0.47-0.99, p = 0.041; odds ratio 0.67, 95% CI 0.46-0.96, p = 0.031). The risks of maternal and neonatal complications were comparable between the two groups.

CONCLUSIONS

In women with a previous failed IVF-ET attempt, immediate FET resulted in higher ongoing pregnancy and live birth rates than delayed FET. These findings warrant caution in the indiscriminate application of a delayed FET strategy when apparent risk of high stress level is perceived.

TRIAL REGISTRATION

ChiCTR2000033313 .

Cumulative delivery rate per aspiration IVF/ICSI cycle in POSEIDON patients: a real-world evidence study of 9073 patients

STUDY QUESTION

What is the cumulative delivery rate (CDR) per aspiration IVF/ICSI cycle in low-prognosis patients as defined by the Patient-Oriented Strategies Encompassing IndividualizeD Oocyte Number (POSEIDON) criteria?

SUMMARY ANSWER

The CDR of POSEIDON patients was on average ∼50% lower than in normal responders and varied across POSEIDON groups; differences were primarily determined by female age, number of embryos obtained, number of embryo transfer (ET) cycles per patient, number of oocytes retrieved, duration of infertility, and BMI.

WHAT IS KNOWN ALREADY

The POSEIDON criteria aim to underline differences related to a poor or suboptimal treatment outcome in terms of oocyte quality and quantity among patients undergoing IVF/ICSI, and thus, create more homogenous groups for the clinical management of infertility and research. POSEIDON patients are presumed to be at a higher risk of failing to achieve a live birth after IVF/ICSI treatment than normal responders with an adequate ovarian reserve. The CDR per initiated/aspiration cycle after the transfer of all fresh and frozen–thawed/warmed embryos has been suggested to be the critical endpoint that sets these groups apart. However, no multicenter study has yet substantiated the validity of the POSEIDON classification in identifying relevant subpopulations of patients with low-prognosis in IVF/ICSI treatment using real-world data.

STUDY DESIGN, SIZE, DURATION

Multicenter population-based retrospective cohort study involving 9073 patients treated in three fertility clinics in Brazil, Turkey and Vietnam between 2015 and 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were women with infertility between 22 and 42 years old in their first IVF/ICSI cycle of standard ovarian stimulation whose fresh and/or frozen embryos were transferred until delivery of a live born or until all embryos were used. Patients were retrospectively classified according to the POSEIDON criteria into four groups based on female age, antral follicle count (AFC), and the number of oocytes retrieved or into a control group of normal responders (non-POSEIDON). POSEIDON patients encompassed younger (<35 years) and older (35 years or above) women with an AFC ≥5 and an unexpected poor (<4 retrieved oocytes) or suboptimal (4–9 retrieved oocytes) response to stimulation, and respective younger and older counterparts with an impaired ovarian reserve (i.e. expected poor responders; AFC <5). Non-POSEIDON patients were those with AFC ≥5 and >9 oocytes retrieved. CDR was computed per one aspirated cycle. Logistic regression analysis was carried out to examine the association between patient classification and CDR.

MAIN RESULTS AND ROLE OF CHANCE

The CDR was lower in the POSEIDON patients than in the non-POSEIDON patients (33.7% vs 50.6%; P < 0.001) and differed across POSEIDON groups (younger unexpected poor responder [Group 1a; n = 212]: 27.8%, younger unexpected suboptimal responder [Group 1b; n = 1785]: 47.8%, older unexpected poor responder [Group 2a; n = 293]: 14.0%, older unexpected suboptimal responder [Group 2b; n = 1275]: 30.5%, younger expected poor responder [Group 3; n = 245]: 29.4%, and older expected poor responder [Group 4; n = 623]: 12.5%. Among unexpected suboptimal/poor responders (POSEIDON Groups 1 and 2), the CDR was twice as high in suboptimal responders (4–9 oocytes retrieved) as in poor responders (<4 oocytes) (P = 0.0004). Logistic regression analysis revealed that the POSEIDON grouping, number of embryos obtained, number of ET cycles per patient, number of oocytes collected, female age, duration of infertility and BMI were relevant predictors for CDR (P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

Our study relied on the antral follicle count as the biomarker used for patient classification. Ovarian stimulation protocols varied across study centers, potentially affecting patient classification.

WIDER IMPLICATIONS OF THE FINDINGS

POSEIDON patients exhibit lower CDR per aspirated IVF/ICSI cycle than normal responders; the differences are mainly determined by female age and number of oocytes retrieved, thereby reflecting the importance of oocyte quality and quantity. Our data substantiate the validity of the POSEIDON criteria in identifying relevant subpopulations of patients with low-prognosis in IVF/ICSI treatment. Efforts in terms of early diagnosis, prevention, and identification of specific interventions that might benefit POSEIDON patients are warranted.

STUDY FUNDING/COMPETING INTEREST(S)

Unrestricted investigator-sponsored study grant (MS200059_0013) from Merck KGaA, Darmstadt, Germany. The funder had no role in study design, data collection, analysis, decision to publish or manuscript preparation. S.C.E. declares receipt of unrestricted research grants from Merck and lecture fees from Merck and Med.E.A. H.Y. declares receipt of payment for lectures from Merck and Ferring. L.N.V. receives speaker fees and conferences from Merck, Merck Sharp and Dohme (MSD) and Ferring and research grants from MSD and Ferring. J.F.C. declares receipt of statistical services fees from ANDROFERT Clinic. T.M.H. received speaker fees and conferences from Merck, MSD and Ferring. P.H. declares receipt of unrestricted research grants from Merck, Ferring, Gedeon Richter and IBSA and lecture fees from Merck, Gedeon Richter and Med.E.A. C.A. declares receipt of unrestricted research grants from Merck and lecture fees from Merck. The remaining authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.