Clinical effectiveness of elective single versus double embryo transfer: meta-analysis of individual patient data from randomised trials

Predicting IVF live -birth probability using time-lapse data: Implications of including or excluding age in a day 2 embryo transfer model

The primary objective of this study was to develop predictive models for the likelihood of live births following In Vitro Fertilisation (IVF) treatment, based on a retrospective analysis of time-lapse data from Day 2 embryo transfers at Klinikk Hausken, Norway. This analysis encompassed 1,506 IVF treatment cycles, which included 865 single and 641 double embryo transfer cycles, totalling 2,147 embryos transferred. The model covariates included nucleation error, timing of two-cell stage (t2) and duration between t2 and the three-cell stage (t3). The predictive ability was assessed using Area Under Curve (AUC). Generalised Additive Mixed Models (GAMM) were utilised to address clustering effects from Single Embryo Transfers (SET) and Double Embryo Transfers (DETs), as well as the non-linear effects of female age and t2 timings. A stratification of age and model scores demonstrated the impact of incorporating age into the model. The" Base Model, not incorporating age, achieved an AUC of 0.641, while the "Age Model", using maternal age, significantly enhanced AUC to 0.745, as estimated through bootstrap analysis. However, when the Age Model was subjected to average ages across three respective age intervals, the AUC values were comparable to the Base Model, rather than the original Age Model scores. Adjusting the Intracytoplasmic Sperm Injection (ICSI) timing by ± 2 hours, purely as a theoretical exercise, has minimal impacts on model predictions. This highlights the value of including t2 despite fertilisation timing variations between ICSI and IVF. The Age Model did not show superiority in predicting live birth within single treatment cohorts. However, given its distinct AUC values for broader age ranges, the Age Model can serve as a counselling tool on live-birth probabilities. With further validation, we suggest only using the Age Model for general counselling, while the Base Model is preferable for the embryo selection decision support.

Maternal Morbidity and Medically Assisted Reproduction Treatment Types

OBJECTIVE

To compare odds of maternal morbidity by mode of becoming pregnant and type of medically assisted reproduction treatments: fertility-enhancing drugs, intrauterine insemination (IUI), and assisted reproductive technology (ART) with autologous or donor oocytes.

METHODS

Birth certificates were used to study maternal morbidity among the birthing population in Utah between 2009 and 2017 (N=469,919 deliveries); 22,543 pregnancies occurred through medically assisted reproduction (4.8%). Maternal morbidity was identified as a binary variable, indicating the presence of any of the following: blood transfusion, unplanned operating room procedure, admission to intensive care unit, eclampsia, unplanned hysterectomy, and ruptured uterus. Using logistic regression, we assessed maternal morbidity among medically assisted reproduction pregnancies (overall and by type of treatment) compared with unassisted pregnancies in the overall sample before and after adjustment for individual sociodemographics (age at birth, family structure, level of education, Hispanic origin, parity), and pre-existing comorbidities (ie, chronic hypertension, heart disease, asthma), multifetal gestation, and obstetric comorbidities (ie, placenta previa, placental abruption, cesarean delivery).

RESULTS

Individuals becoming pregnant through medically assisted reproduction had higher risk of maternal morbidity, with odds ratios (ORs) increasing as medically assisted reproduction treatments become more invasive. Associations were largely attenuated when accounting for multifetal gestation and further reduced after controlling for obstetric comorbidities. However, ART with autologous oocytes (OR 1.46, 95% CI, 1.20-1.78) maintained higher coefficients compared with unassisted pregnancies. In models including only singletons, after controlling for obstetric comorbidities, the OR differences in maternal morbidity between all medically assisted reproduction groups and unassisted pregnancies were no longer statistically significant.

CONCLUSION

More invasive medically assisted reproduction treatments (ART and IUI) are associated with higher odds of maternal morbidity, whereas less invasive treatments are not. This relationship is partially explained by higher prevalence of multifetal gestation and obstetric comorbidities in people undergoing more invasive treatment, but the persistent association suggests subfertility itself may contribute to maternal morbidity.

How to balance the live birth rate and the multiple pregnancy rate by selecting the cleavage-stage embryo number and quality for POSEIDON Group 1 and Group 2? A retrospective study

PURPOSE

For unexpected low-prognosis patients (Group 1 and Group 2) defined by POSEIDON criteria, how to maximize the live birth rate while controlling the multiple birth rate by tailoring the embryo transfer number and quality?

METHODS

This was a retrospective study, including patients from Poseidon Group 1 (N = 672) and Group 2 (N = 503) who underwent cleavage-stage embryo transfer. Logistic regression was used for the comparative analysis of clinical outcomes among subgroups divided by the number and quality of embryos.

RESULTS

For Group 1, compared to transferring a single good-quality embryo (GQE), a good-quality embryo with a poor-quality embryo (GQE + PQE) did not significantly improve the live birth rate, although increasing in value (40.5% vs 31.9%, P = 0.272), meanwhile obviously raised the multiple birth rate to 28.1% (P = 0.042). For Group 2, double embryo transfer (DET) was associated with a higher live birth rate than single embryo transfer (SET) (22.4% vs 6.3%, P = 0.001) and further analysis indicated that the similar trend observed in the GQE + PQE group compared to the GQE group (26.1% vs 8.5%, P = 0.017) with statistical significance, but without a significant increase in the multiple birth rate (8.3%, P = 1.000).

CONCLUSIONS

The study indicated that  a single good-quality cleavage-stage embryo was an option for patients in Poseidon Group 1 to avoid the risk of multiple pregnancies. DET with mixed quality cleavage-stage embryo might be an alternative for Poseidon Group 2, given that it improved the pregnancy outcomes while controlling the multiple birth rates.

A modified flexible GnRH antagonist protocol using antagonist early cessation and a gonadotropin step-down approach improves live birth rates in fresh cycles: a randomized controlled trial

STUDY QUESTION

Can pregnancy outcomes following fresh elective single embryo transfer (eSET) in gonadotropin-releasing hormone (GnRH) antagonist protocols increase using a gonadotropin (Gn) step-down approach with cessation of GnRH antagonist on the day of hCG administration (hCG day) in patients with normal ovarian response?

SUMMARY ANSWER

The modified GnRH antagonist protocol using the Gn step-down approach and cessation of GnRH antagonist on the hCG day is effective in improving live birth rates (LBRs) per fresh eSET cycle.

WHAT IS KNOWN ALREADY

Currently, there is no consensus on optimal GnRH antagonist regimens. Studies have shown that fresh GnRH antagonist cycles result in poorer pregnancy outcomes than the long GnRH agonist (GnRHa) protocol. Endometrial receptivity is a key factor that contributes to this phenomenon.

STUDY DESIGN, SIZE, DURATION

An open label randomized controlled trial (RCT) was performed between November 2021 and August 2022. There were 546 patients allocated to either the modified GnRH antagonist or the conventional antagonist protocol at a 1:1 ratio.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Both IVF and ICSI cycles were included, and the sperm samples used were either fresh or frozen from the partner, or from frozen donor ejaculates. The primary outcome was the LBRs per fresh SET cycle. Secondary outcomes included rates of implantation, clinical and ongoing pregnancy, miscarriage, and ovarian hyperstimulation syndrome (OHSS), as well as clinical outcomes of ovarian stimulation.

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline demographic features were not significantly different between the two ovarian stimulation groups. However, in the intention-to-treat (ITT) population, the LBRs in the modified antagonist group were significantly higher than in the conventional group (38.1% [104/273] vs. 27.5% [75/273], relative risk 1.39 [95% CI, 1.09-1.77], P = 0.008). Using a per-protocol (PP) analysis which included all the patients who received an embryo transfer, the LBRs in the modified antagonist group were also significantly higher than in the conventional group (48.6% [103/212] vs. 36.8% [74/201], relative risk 1.32 [95% CI, 1.05-1.66], P = 0.016). The modified antagonist group achieved significantly higher implantation rates, and clinical and ongoing pregnancy rates than the conventional group in both the ITT and PP analyses (P < 0.05). The two groups did not show significant differences between the number of oocytes retrieved or mature oocytes, two-pronuclear zygote (2PN) rates, the number of embryos obtained, blastocyst progression and good-quality embryo rates, early miscarriage rates, or OHSS incidence rates (P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

A limitation of our study was that the subjects were not blinded to the treatment allocation in the RCT trial. Only women under 40 years of age who had a good prognosis were included in the analysis. Therefore, use of the modified antagonist protocol in older patients with a low ovarian reserve remains to be investigated. In addition, the sample size for Day 5 elective SET was small, so larger trials will be required to strengthen these findings.

WIDER IMPLICATIONS OF THE FINDINGS

The modified GnRH antagonist protocol using the Gn step-down approach and cessation of GnRH antagonist on hCG day improved the LBRs per fresh eSET cycle in normal responders.

STUDY FUNDING/COMPETING INTEREST(S)

This project was funded by grant 2022YFC2702503 from the National Key Research & Development Program of China and grant 2021140 from the Beijing Health Promotion Association. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

The RCT was registered in the Chinese Clinical Trial Registry; Study Number: ChiCTR2100053453.

TRIAL REGISTRATION DATE

21 November 2021.

DATE OF FIRST PATIENT’S ENROLLMENT

23 November 2021.

Impact of inclusion of a poor-quality embryo with a good-quality embryo on pregnancy outcomes in vitrified-warmed blastocyst transfers

RESEARCH QUESTION

Does the co-transfer of a good-quality embryo and a poor-quality embryo influence pregnancy outcomes in comparison to the transfer of a single good-quality embryo in vitrified-warmed blastocyst transfer cycles?

DESIGN

This retrospective cohort study involved a total of 11,738 women who underwent IVF/intracytoplasmic sperm injection cycles and vitrified-warmed blastocyst transfer at a tertiary-care academic medical from January 2015 to June 2022. The study population was categorized into two groups: single-blastocyst transfer (SBT; participants who underwent single good-quality embryo transfer, n = 9338) versus double-blastocyst transfer (DBT; participants who underwent transfers with a poor and a good-quality embryo, n = 2400).

RESULTS

The live birth rate (LBR) was significantly higher in the DBT group in comparison with the SBT group (65.6% versus 56.3%, P < 0.001). Multivariable logistic regression analysis showed that DBT was an independent predictor for LBR with a strong potential impact (adjusted odds ratio 1.55, 95% confidence interval 1.41-1.71; P < 0.001). However, the multiple birth rate was significantly higher in the good-quality embryo and poor-quality embryo group compared with patients undergoing a single good-quality embryo transfer (41.4% versus 1.8%; P < 0.001).

CONCLUSIONS

In vitrified-warmed blastocyst transfer cycles, LBR was higher following DBT with one good-quality and one poor-quality embryo compared with SBT. However, this was at the expense of a marked increase in the likelihood of multiple gestations. Physicians should still balance the benefits and risks of double-embryo transfer.

Analysis of factors influencing pregnancy and its outcomes in women undergoing in vitro fertilization-embryo transfer/frozen embryo transfer cycles: A retrospective study

The relationship between clinical outcomes and various factors influencing pregnancy was analyzed to provide reference data for patients and clinicians when selecting embryo transfer protocols. This was a retrospective study of 1309 transfer cycles between June 1, 2018, and May 1, 2023, in the Reproductive Medicine Center. Univariate analysis was performed on various factors that may have affected pregnancy outcomes, and further regression analysis was performed on those factors found by univariate analysis to correlate positively with clinical pregnancy outcomes. Finally, the embryo transfer schemes were compared based on the analysis results. The results showed that the stage of embryonic development significantly affected pregnancy outcomes after transplantation (P < .01, 95% confidence interval: 2.554 [1.958-3.332]). There was no significant difference in the pregnancy rate between 1 high-quality blastocyst transfer and 2 cleavage-stage embryos or blastocyst transfer (64.22% vs 70.11%, P = .439); however, the rate of multiple pregnancies after 1 high-quality blastocyst transfer was close to the rate of natural conception. These data show that the transfer of single high-quality blastocysts can significantly reduce the multiple pregnancy rate while ensuring an ideal pregnancy rate, which can be used as a reference for planning the first transplantation in patients with good prognoses.

The impacts of telemedicine on assisted reproduction: a systematic review and meta-analysis

Telemedicine is being applied in assisted reproduction technology (ART) to provide remote consultations, monitoring and support for patients. This study aimed to evaluate the potential advantages of telemedicine in ART treatment in the form of virtual consultations. Studies in which patients were using telemedicine during ART treatment were identified from four scientific databases (PudMed, EMBASE, Scopus, Web of Science). The success of fertility treatments was compared between telemedicine and in-office care, and patient satisfaction with ART through telemedicine was assessed. Eleven studies, comprising 4697 patients, were identified. Quality assessment (Joanna Briggs Institute Critical Appraisal and revised Cochrane risk-of-bias tools) revealed an acceptable risk of bias for both randomized controlled trials and observational studies. Using a fixed-effects model, telemedicine was comparable to in-person care regarding the pregnancy rate achieved (odds ratio 1.02, 95% confidence intervals 0.83-1.26, P = 0.83). A Q-test suggested that all the included studies were homogeneous. Patients who received telemedicine during fertility treatment reported a high level of satisfaction (91%, 95% confidence intervals 80-96%). Egger's test confirmed that no publication bias was found. Telemedicine could serve as a complementary tool during fertility treatment to facilitate patients' satisfaction and overcome some practical problems without compromising treatment outcomes. Future studies should continue exploring the potential applications of telemedicine in assisted reproduction.

Analysis of predictors of clinical pregnancy and live birth in patients with RIF treated with IVF-ET technology: a cohort study based on a propensity score approach

Objective

To investigate the predictors of clinical pregnancy and live birth rate in patients with recurrent embryo implantation failure (RIF) treated with in vitro fertilization-embryo transfer (IVF-ET) technique.

Method

This retrospective cohort study was conducted in Jinjiang District Maternal and Child Health Hospital, Chengdu City, Sichuan Province, China. Patients were recruited who were enrolled at this hospital between November 1, 2019 and August 31, 2022, and who met the following criteria: a frozen embryo transfer (FET) at day 5 or 6 blastocyst stage was performed and the number of transfer cycles was not less than two. We collected information on age, height, weight, number of embryo transfer cycles, and information related to clinical outcomes. We used the group of patients who underwent ERA testing as the study group and those who underwent FET only as the control group, and matched baseline characteristics between the two groups by propensity score to make them comparable. We compared the differences in clinical outcomes between the two groups and further explored predictors of pregnancy and live birth using survival analysis and COX regression modeling.

Results

The success rate of clinical pregnancy in RIF patients was 50.74% and the live birth rate was 33.09%. Patients in the FET group were less likely to achieve clinical pregnancy compared to the ERA group (HR = 0.788, 95%CI 0.593-0.978, p < 0.05). Patients with >3 previous implantation failures had a lower probability of achieving a clinical pregnancy (HR = 0.058, 95%CI 0.026-0.128, p < 0.05) and a lower likelihood of a live birth (HR = 0.055, 95%CI 0.019-0.160, p < 0.05), compared to patients with ≤3 previous implantation failures. Patients who had two embryos transferred were more likely to achieve a clinical pregnancy (HR = 1.357, 95%CI 1.079-1.889, p < 0.05) and a higher likelihood of a live birth (HR = 1.845, 95%CI 1.170-2.910, p < 0.05) than patients who had a single embryo transfer. Patients with concomitant high-quality embryo transfer were more likely to achieve a clinical pregnancy compared to those without high-quality embryo transfer (HR = 1.917, 95%CI 1.225-1.863, p < 0.05).

Conclusion

Not receiving an ERA, having >3 previous implantation failures, using single embryo transfer and not transferring quality embryos are predictors for clinical pregnancy in patients with RIF. Having>3 previous implantation failures and using single embryo transfer were predictors for live birth in patients with RIF.

Multifetal Pregnancy After Implementation of a Publicly Funded Fertility Program

Importance

A publicly funded fertility program was introduced in Ontario, Canada, in 2015 to increase access to fertility treatment. For in vitro fertilization (IVF), the program mandated an elective single-embryo transfer (eSET) policy. However, ovulation induction and intrauterine insemination (OI/IUI)-2 other common forms of fertility treatment-were more difficult to regulate in this manner. Furthermore, prior epidemiologic studies only assessed fetuses at birth and did not account for potential fetal reductions that may have been performed earlier in pregnancy.

Objective

To examine the association between fertility treatment and the risk of multifetal pregnancy in a publicly funded fertility program, accounting for both fetal reductions and all live births and stillbirths.

Design, Setting, and Participants

This population-based, retrospective cohort study used linked administrative health databases at ICES to examine all births and fetal reductions in Ontario, Canada, from April 1, 2006, to March 31, 2021.

Exposure

Mode of conception: (1) unassisted conception, (2) OI/IUI, or (3) IVF.

Main Outcomes and Measures

The main outcome was multifetal pregnancy (ie, a twin or higher-order pregnancy). Modified Poisson regression generated adjusted relative risks (ARRs) and derived population attributable fractions (PAFs) for multifetal pregnancies attributable to fertility treatment. Absolute rate differences (ARDs) were used to compare the era before eSET was promoted (2006-2011) with the era after the introduction of the eSET mandate (2016-2021).

Results

Of all 1 724 899 pregnancies, 1 670 825 (96.9%) were by unassisted conception (mean [SD] maternal age, 30.6 [5.2] years), 24 395 (1.4%) by OI/IUI (mean [SD] maternal age, 33.1 [4.4] years), and 29 679 (1.7%) by IVF (mean [SD] maternal age, 35.8 [4.7] years). In contrast to unassisted conception, individuals who received OI/IUI or IVF tended to be older, reside in a high-income quintile neighborhood, or have preexisting health conditions. Multifetal pregnancy rates were 1.4% (95% CI, 1.4%-1.4%) for unassisted conception, 10.5% (95% CI, 10.2%-10.9%) after OI/IUI, and 15.5% (95% CI, 15.1%-15.9%) after IVF. Compared with unassisted conception, the ARR of any multifetal pregnancy was 7.0 (95% CI, 6.7-7.3) after OI/IUI and 9.9 (95% CI, 9.6-10.3) after IVF, with corresponding PAFs of 7.1% (95% CI, 7.1%-7.2%) and 13.4% (95% CI, 13.3%-13.4%). Between the eras of 2006 to 2011 and 2016 to 2021, multifetal pregnancy rates decreased from 12.9% to 9.1% with OI/IUI (ARD, -3.8%; 95% CI, -4.2% to -3.4%) and from 29.4% to 7.1% with IVF (ARD, -22.3%; 95% CI, -23.2% to -21.6%).

Conclusions and Relevance

In this cohort study of more than 1.7 million pregnancies in Ontario, Canada, a publicly funded IVF program mandating an eSET policy was associated with a reduction in multifetal pregnancy rates. Nevertheless, ongoing strategies are needed to decrease multifetal pregnancy, especially in those undergoing OI/IUI.

Prediction of live birth - selection of embryos using morphokinetic parameters

BACKROUND

The goal of assisted reproduction is for a couple treated with IVF techniques to end the treatment by giving birth to a healthy baby. A neccessary presumption for success is the identification of the best embryo with high implantation and developmental potential. One option is to select an euploid embryo by invasive preimplantaion genetic testing for aneuploidy (PGT-A) or it is possible to select the best embryo by non-invasive time-lapse monitoring (TLM), specifically based on morphokinetic parameters and morphological markers that are able to identify an embryo with high developmental potential.

MATERIALS AND METHODS

The study involved a total of 1060 embryos (585 euploid and 475 aneuploid embryos after PGT-A) with good morphology from 329 patients in the period 01/2016-10/2021. All embryos were cultured in a time-lapse incubator, trophectoderm (TE) cells biopsies for PGT-A examination were performed on day 5 (D5) or day 6 (D6) of culture. During the study period, 225 frozen embryo transfers (FET) of one euploid embryo were performed. Based on the treatment outcome, the embryos were divided into 2 groups - euploid embryos, which led to the birth of a healthy child, and euploid embryos that did not show fetal heartbeat (FHB) after FET.

RESULTS

Based on the statistical analysis of the embryos without implantation and the embryos with live birth, it is clear that the morphokinetic parameters t5 (time of division into 5 cells) and tSB (time of start of blastulation) are significantly different.

CONCLUSION

The results suggest that of the morphokinetic parameters tSB and t5 are predictive indicators for selecting an embryo with high developmental potential and with a high probability of achieving the birth of a healthy child.

Single versus double blastocyst transfer in first and second frozen-thawed embryo transfer cycle in advance-aged women: a two-center retrospective cohort study

BACKGROUND

The present evidence is deficient for the trade-offs between the pros and cons of single blastocyst transfer (SBT) versus double blastocyst transfer (DBT) in frozen-thawed embryo transfer cycles for women in advanced reproductive age, especially in the second cycle. The current study aimed to investigate the impact of transferred blastocyst numbers on pregnancy outcomes in the first and second embryo transfer for women ≥ 35 years.

METHODS

This was a retrospective cohort study including 1284 frozen-thawed blastocyst transfer (FBT) cycles from two reproductive centers. We analyzed the pregnancy outcomes after SBT and DBT in the first and second FBT cycles. Moreover, stratified analysis was conducted by maternal age.

RESULTS

In the first FBT cycle, the LBR was higher in the DBT group than that in the SBT group [52.3% vs. 33.9%; adjusted odds ratio (aOR), 1.65; 95% confidence interval (CI), 1.26-2.15, P < 0.001]. However, the LBR of the DBT group showed no remarkable difference compared with that of the SBT group in the second cycle of FBT (44.3% vs. 33.3%; aOR, 1.30; 95% CI, 0.81-2.08; P = 0.271). Furthermore, stratified analysis by age showed a higher LBR for the DBT group than the SBT group in patients aged 38-42 years (43.1% vs. 33.9%; aOR, 2.27; 95% CI, 1.05-4.90; P = 0.036).

CONCLUSIONS

The present study demonstrated that the SBT regimen is a better choice for both, the first and second frozen-thawed embryo transfer cycles, for women aged 35-37 years. Additionally, the DBT regimen is still recommended to achieve a high LBR in women aged 38-42 years in the second FBT cycle. These findings may be beneficial for deciding the embryo transfer regimens in women of advanced reproductive age.

The Association of AMH Level with the Number and Quality of Oocytes in Women Undergoing IVF/ICSI: A Single-Center Study

Background

The recognized role of Anti-Müllerian hormone (AMH) as a marker for women's biological age and ovarian reserve prompts debate on its efficacy in predicting oocyte quality during IVF/ICSI. Recent findings challenging this view compelled us to conduct this study to examine the correlation between AMH levels and quantity/quality of oocytes in IVF/ICSI procedures.

Methods

The data were collected retrospectively from the medical records of 320 women between 25-42 years old. The included patients were divided into two groups: the high AMH group (>1.1 ng/ml) and the low AMH (=<1.1 ng/ml) group. The high AMH group comprised 213 patients, while the low AMH group consisted of 107 patients. Spearman's correlation coefficient and Multinomial logistic regression were computed to assess the relationships between different variables.

Results

Significant positive correlations were detected between AMH level and the number of aspirated follicles (rho=0.741, p<0.001), retrieved oocytes (rho=0.659, p<0.001), M2 oocytes (rho=0.624, p<0.001), grade A embryos (rho=0.419, p<0.001), and grade AB embryos (rho=0.446, p<0.001. In contrast, AMH levels had negative associations with the number and duration of cycles (p<0.05). AMH emerged as a statistically significant independent predictor of the number of M2 oocytes.

Conclusions

Serum AMH level could represent the quantity and quality of oocytes following IVF/ICSI treatments. Future studies should aim to delve deeper into the correlations between AMH levels and both the quality and quantity of embryos. Additionally, it would be beneficial to consider the influence of sperm factors, as well as assess pregnancy rates.

Blastocyst quality and reproductive and perinatal outcomes: a multinational multicentre observational study

STUDY QUESTION

Does the transfer of single low-grade blastocysts result in acceptable reproductive and perinatal outcomes compared to the transfer of single good-grade blastocysts?

SUMMARY ANSWER

The transfer of single low-grade blastocysts resulted in a reduced live birth rate of around 30% (14% for very low-grade blastocysts) compared to 44% for single good-grade blastocysts, but does not lead to more adverse perinatal outcomes.

WHAT IS KNOWN ALREADY

It is known that low-grade blastocysts can result in live births. However, the current studies are limited by relatively small sample sizes and single-centre designs. Furthermore, evidence on perinatal outcomes after transferring low-grade blastocysts is limited.

STUDY DESIGN, SIZE, DURATION

We conducted a multi-centre, multi-national retrospective cohort study of 10 018 women undergoing 10 964 single blastocyst transfer cycles between 2009 and 2020 from 14 clinics across Australia, China, and New Zealand.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Blastocysts were graded individually based on assessment of the morphology and development of the inner cell mass (ICM) and trophectoderm (TE), and were grouped into three quality categories: good- (AB, AB, or BA), moderate- (BB), and low-grade (grade C for ICM or TE) blastocysts. CC blastocysts were individually grouped as very low-grade blastocysts. Logistic regression with generalized estimating equation was used to analyse the association between blastocyst quality and live birth as well as other reproductive outcomes. Binomial, multinomial logistic, or linear regression was used to investigate the association between blastocyst quality and perinatal outcomes. Odds ratio (OR), adjusted OR (aOR), adjusted regression coefficient, and their 95% CIs are presented. Statistical significance was set at P < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 4386 good-grade blastocysts, 3735 moderate-grade blastocysts, and 2843 low-grade blastocysts were included in the analysis, for which the live birth rates were 44.4%, 38.6%, and 30.2%, respectively. Compared to good-grade blastocysts, the live birth rate of low-grade blastocysts was significantly lower (aOR of 0.48 (0.41-0.55)). Very low-grade blastocysts were associated with an even lower live birth rate (aOR 0.30 (0.18-0.52)) and their absolute live birth rate was 13.7%. There were 4132 singleton live births included in the analysis of perinatal outcomes. Compared with good-grade blastocysts, low-grade blastocysts had comparable preterm birth rates (<37 weeks, aOR 1.00 (0.65-1.54)), birthweight Z-scores (adjusted regression coefficient 0.02 (0.09-0.14)), and rates of very low birth weight (<1500 g, aOR 0.84 (0.22-3.25)), low birth weight (1500-2500 g, aOR 0.96 (0.56-1.65)), high birth weight (>4500 g, aOR 0.93 (0.37-2.32)), small for gestational age (aOR 1.63 (0.91-2.93)), and large for gestational age (aOR 1.28 (0.97-1.70)).

LIMITATIONS, REASONS FOR CAUTION

Due to the nature of the retrospective design, residual confounding could not be excluded. In addition, the number of events for some perinatal outcomes was small. Between-operator and between-laboratory variations in blastocyst assessment were difficult to control.

WIDER IMPLICATIONS OF THE FINDINGS

Patients undergoing IVF should be informed that low-grade blastocysts result in a lower live birth rate, however they do not increase the risk of adverse perinatal outcomes. Further research should focus on the criteria for embryos that should not be transferred and on the follow-up of long-term outcomes of offspring.

STUDY FUNDING/COMPETING INTEREST(S)

H.Z. is supported by a Monash Research Scholarship. B.W.J.M. is supported by a NHMRC Investigator grant (GNT1176437). R.W. is supported by an NHMRC Emerging Leadership Investigator grant (2009767). B.W.J.M. reports consultancy, travel support, and research funding from Merck. The other authors do not have competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

The effect of embryo selection using time-lapse monitoring on IVF/ICSI outcomes: A systematic review and meta-analysis

AIM

To explore the effect of embryo selection using the time-lapse monitoring (TLM) system compared with conventional morphological selection (CMS) on in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes.

METHODS

We searched PubMed, Ovid-Embase, and The Cochrane Library for the following studies: At Comparison 1, embryo selection using TLM images in a TLM incubator based on morphology versus embryo selection using CMS in a conventional incubator based on morphology; at Comparison 2, embryo selection using TLM based on morphokinetics versus embryo selection using CMS based on morphology. The primary outcomes were the live birth rate (LBR), ongoing pregnancy rate (OPR), clinical pregnancy rate (CPR), and implantation rate (IR), and the secondary outcome was the miscarriage rate (MR).

RESULTS

A total of 14 randomized control trials (RCTs) were included. Both based on morphology, TLM incubators increased the IR (risk ratio [RR]: 1.10; 95% confidence interval [CI]: 1.01, 1.18; I2  = 0%, moderate-quality evidence) compared to conventional incubators. Low- to moderate-quality evidence suggests that TLM incubators did not improve LBR, OPR, CPR, and MR compared to conventional incubators. In addition, low- to moderate-quality evidence indicates that embryo selection using TLM based on morphokinetics did not improve LBR, OPR, CPR, IR, or MR compared to CMS based on morphology.

CONCLUSIONS

Low- to moderate-quality evidence suggests that neither TLM incubators nor embryo selection using TLM based on morphokinetics improved clinical outcomes (LBR, OPR, CPR, and MR) compared with CMS based on morphology. TLM is still an investigational procedure for IVF/ICSI practice.

Fertility treatment increases the risk of preterm birth independent of multiple gestations

Objective

To investigate the complex interplay between fertility treatment, multiple gestations, and prematurity.

Design

Retrospective cohort study linking the national Center for Disease Control and Prevention infant birth and death data from 2014 to 2018.

Setting

National database from Center of Disease Control and Prevention.

Patients

In total, 19,454,155 live-born infants with gestational ages 22-44 weeks, 114,645 infants born using non IVF fertility treatment (NIFT), and 179,960 via assisted reproductive technology (ART).

Intervention

Noninvasive fertility treatment or ART vs. spontaneously conceived pregnancies.

Main Outcome Measures

The main outcome assessed was prematurity. Formal mediation analysis was conducted to calculate the percentage mediated by multiple gestations.

Results

Newborns born using NIFT or ART compared with those with no fertility treatment had a higher incidence of multiple gestation (no fertility treatment = 3.0%; NIFT = 24.7%; ART = 32.7%; P<.001) and prematurity (no fertility treatment = 11.2%; NIFT = 23.4%; ART = 28.4%; P<.001). Mediation analysis demonstrates that 76.8% (95% confidence interval [CI], 75.2%-78.1%) of the effect of NIFT on prematurity was mediated through multiple gestations. Similarly, 71.2% (95% CI, 70.8%-72.7%) of the effect of ART on prematurity is mediated through multiple gestation. However, the direct effect of NIFT on prematurity is 20.4% (95% CI, 19.0%-22.0%). The direct effect of ART was 24.7% (95% CI, 23.7%-25.6%).

Conclusion

A significant proportion of prematurity associated with fertility treatment is mediated by the treatment itself, independent of multiple gestations.

A comparison of the morphokinetic profiles of embryos developed from vitrified versus fresh oocytes

RESEARCH QUESTION

Do morphokinetic profiles and treatment outcomes differ between embryos developed from vitrified or fresh oocytes?

DESIGN

Retrospective multicentre analysis using data from eight CARE Fertility clinics across the UK between 2012 and 2019. Patients receiving treatment using embryos developed from vitrified oocytes (n = 118 women, n = 748 oocytes), providing 557 zygotes during this time period, were recruited and matched with patients undergoing treatment with embryos developed from fresh oocytes (n = 123 women, n = 1110 oocytes), providing 539 zygotes in the same time frame. Time-lapse microscopy was used to assess morphokinetic profiles, including early cleavage divisions (2- through to 8-cell), post-cleavage stages including time to start of compaction, time to morula, time to start of blastulation and time to full blastocyst. Duration of key stages such as the compaction stage were also calculated. Treatment outcomes were compared between the two groups (live birth rate, clinical pregnancy rate and implantation rate).

RESULTS

A significant delay of 2-3 h across all early cleavage divisions (2- through to 8-cell) and time to start of compaction occurred in the vitrified group versus fresh controls (all P ≤ 0.01). The compaction stage was significantly shorter in vitrified oocytes (19.02 ± 0.5 h) compared with fresh controls (22.45 ± 0.6 h, P < 0.001). There was no difference in the time that fresh and vitrified embryos reached the blastocyst stage (108.03 ± 0.7 versus 107.78 ± 0.6 h). There was no significant difference in treatment outcomes between the two groups.

CONCLUSION

Vitrification is a useful technique for extending female fertility with no effects on IVF treatment outcome.

Acceptance of Elective Single-embryo Transfer in a Resource-limited Setting: A Cross-sectional Questionnaire-based Study

Background

While elective single-embryo transfer (eSET) has been advocated in select countries, the global acceptance of the eSET policy has been undermined due to various issues. It is imperative to understand the couples' perspectives regarding the number of embryos transferred.

Aims

We planned a study to evaluate the knowledge and attitude of infertile couples undergoing assisted reproductive technology towards eSET in self-funded treatment cycles in a low-resource setting.

Settings and Design

We conducted a cross-sectional study at a tertiary-level referral facility between February 2020 and September 2022.

Materials and Methods

This was an interviewer-administered questionnaire-based survey in two stages. The first stage involved the assessment of the knowledge of the participants. Following this, participants were given an information pamphlet and the second stage of the interview was conducted to assess the attitude and change in preference for embryo transfer number.

Statistical Analysis Used

The Chi-square and Fisher's exact test were applied to find an association between categorical variables. Logistic regression was used to assess the association between factors and outcomes.

Results

eSET was the preferred choice for only 5.8% of the participants. Following our educational intervention using an information leaflet, there was a statistically significant increase in the preference for eSET (P = 0.01). Univariate logistic regression analysis revealed that participants with a monthly income of ≤50,000 INR had a significantly higher preference for eSET.

Conclusion

Continued emphasis on the risks of double-embryo transfer coupled with individualised selection criteria for eSET may help to achieve reasonable congruency between the clinician and couples' decision.

The cost of preterm birth and cesarean section as a result of infertility and its treatment: A review

Infertility, irrespective of receipt of fertility treatment, is associated with an increased risk of adverse pregnancy outcomes, including cesarean section (CS) and preterm birth (PTB). These complications are associated with significant physical, mental, emotional, social, and financial costs to individuals, healthcare systems, and society at large. Although multiple pregnancy is one of the most significant contributors to the elevated CS and PTB rates in women receiving fertility treatment, singleton pregnancy is also at an increased risk of these outcomes. Single embryo transfer policies through publicly funded in vitro fertilization programs have demonstrated beneficial health outcomes and cost savings. Low-dose aspirin prophylaxis may be considered for PTB reduction in patients with infertility. Finally, upstream prevention strategies such as lifestyle modification and social policies to address the underlying needs for fertility treatment may also beneficially impact both CS and PTB rates.

Live birth is not the only relevant outcome in research assessing assisted reproductive technology

In assisted reproductive technology (ART) research, live birth has been generally accepted as an important outcome, if not the most important one. However, it has been reported inconsistently in the literature and solely focusing on live birth can lead to misinterpretation of research findings. In this review, we provide an overview on the definitions of live birth, including various denominators and numerators use. We present a series of real clinical examples in ART research to demonstrate the impact of variations in live birth on research findings and the importance of other outcomes, including multiple pregnancy, pregnancy loss, time to pregnancy leading to live birth, other short and long term maternal and offspring health outcomes and cost effectiveness measures. We suggest that outcome choices in ART research should be tailored for the research questions. A holistic outcome assessment beyond live birth would provide a full picture to address research questions in ART in terms of effectiveness and safety, and thus facilitate evidence-based decision making.

Risk Factors of Pregnancy Failure in Infertile Patients Undergoing Assisted Reproductive Technology

Background

Infertile couples need to use assisted reproductive technology (ART) to give birth. However, pregnancy failure after ART is not uncommon. At present, the results of studies on the causes of pregnancy failure after ART are inconsistent.

Methods

A retrospective cohort study involving 715 embryo transfer cycles was conducted at the Reproductive Medicine Center of Meizhou People's Hospital, from December 2015 to June 2022. According to the pregnancy, they were divided into clinical pregnancy group and pregnancy failure group. The relationship between demographic characteristics and pregnancy status between the two groups was analyzed.

Results

The pregnancy failure rate after ART was 49.7% (355/715). There were statistically significant distribution differences of maternal age, paternal age, COH protocols, and number of embryos transferred between clinical pregnancy and pregnancy failure groups (all P<0.01). Multiple logistic regression analysis shows that high maternal age (>35 years old vs ≤35 years old: OR 2.173, 95% CI: 1.386-3.407, P=0.001), and GnRH-a short protocol (GnRH-a short protocol vs GnRH-a long protocol: OR 2.139, 95% CI: 1.127-4.058, P=0.020) may increase risk of pregnancy failure in ART pregnancies, while two embryos transferred (two embryos transferred vs one embryo transferred: OR 0.563, 95% CI: 0.377-0.839, P=0.005) may reduce risk of pregnancy failure. In addition, high maternal age, GnRH antagonist protocol, and GnRH-a short protocol may increase risk of implantation failure, while two embryos transferred may reduce risk of implantation failure. And high maternal age may increase risk of biochemical pregnancy.

Conclusion

The risk of pregnancy failure increased in ART cycles with maternal age >35 years old and GnRH-a short protocol, while reduced with two embryos transferred.

The effect of progesterone supplementation for luteal phase support in natural cycle frozen embryo transfer: a systematic review and meta-analysis based on randomized controlled trials

IMPORTANCE

The necessity of progesterone supplementation for luteal phase support (LPS) in natural cycle frozen embryo transfer (NC-FET) cycles warrants further confirmation.

OBJECTIVE

To investigate the effect of progesterone supplementation for LPS on the reproductive outcomes of patients undergoing NC-FET cycles.

DATA SOURCES

The PubMed, Ovid-Embase, Cochrane Library, Web of Science, CNKI, Wanfang, VIP, and CBM were electronically searched. The search time frame was from inception up to September 2022.

STUDY SELECTION AND SYNTHESIS

Randomized controlled trials (RCTs) that used progesterone for LPS in NC-FET cycles, including true NC-FET cycles (tNC-FET) and modified NC-FET cycles (mNC-FET), were included. The counted data were analyzed using relative risk (RR) as the effect-size statistic, and each effect size was assigned its 95% confidence interval (CI).

MAIN OUTCOME MEASURES

The primary outcomes were the live birth rate (LBR) and the clinical pregnancy rate (CPR), and the secondary outcome was the miscarriage rate.

RESULTS

Four RCTs were included, which involved 1116 participants. The results of the meta-analysis showed that progesterone supplementation was associated with increased LBR (RR, 1.42; 95% CI, 1.15-1.75; I² = 0%, moderate-quality evidence) and CPR (RR, 1.30, 95% CI, 1.07-1.57; I² = 0%, moderate-quality evidence) in patients undergoing NC-FET cycles. Subgroup analysis showed that progesterone supplementation was associated with higher LBR and CPR in tNC-FET cycles. However, no association was found between increased LBR and CPR in mNC-FET cycles. In addition, only one RCT reported that oral dydrogesterone had similar CPR and miscarriage rate compared with vaginal progesterone in mNC-FET cycles.

CONCLUSION(S)

Overall, moderate-quality evidence suggested that progesterone supplementation for LPS was associated with increased LBR and CPR in NC-FET cycles. Progesterone supplementation was associated with a higher LBR and CPR in tNC-FET cycles. However, the effectiveness of progesterone supplementation in mNC-FET cycles should be further verified by larger RCTs. Low to very low-quality evidence indicated that oral dydrogesterone and vaginal progesterone have similar reproductive outcomes in mNC-FET cycles, which requires further study, especially in tNC-FET cycles.

REGISTRATION NUMBER

PROSPERO CRD42022355550 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=355550) was registered on September 3, 2022.

Obstetric and Perinatal Outcomes of Singleton Births Following Single- vs Double-Embryo Transfer in Sweden

Importance

Pregnancies resulting from assisted reproductive technology are associated with an increased risk of adverse perinatal outcomes compared with those following natural conception. Previous studies have shown an association of pregnancies resulting from transfer of multiple embryos with these negative findings.

Objective

To determine the risk for adverse outcomes in singletons conceived through assisted reproduction using double-embryo transfer (DET) vs single-embryo transfer (SET).

Design, Setting, and Participants

This cohort study used data from women who achieved singleton deliveries after SET or DET in Sweden between 2007 and 2017 as recorded in the National Quality Registry for Assisted Reproduction. All embryo transfers, at cleavage or blastocyst stage, replaced in fresh or frozen treatment cycles were included. Data on obstetric and neonatal outcomes were retrieved by linkage to the National Medical Birth Register. Naturally conceived singletons were included as a reference group. Data were analyzed between September 2021 and August 2022.

Exposures

Double-embryo transfer leading to singleton birth.

Main Outcomes and Measures

Relative risk ratios or odds ratios (ORs) and absolute risk differences (ARDs) in percentage points with 95% CIs were calculated for obstetric and perinatal outcomes in singleton births conceived using DET vs SET.

Results

Among 1 115 863 singleton births, 30 713 singletons were born after SET and 5123 after DET. A higher risk of neonatal death was found in singletons after DET vs SET (OR, 2.67 [95% CI, 1.28-5.55]; ARD, 0.2 percentage points [95% CI, 0.0-0.4 percentage points]). In frozen embryo transfers, DET was associated with a higher risk of low birth weight (OR, 1.64 [95% CI, 1.19-2.25]; ARD, 2.0 percentage points [95% CI, 0.5-3.5 percentage points]). Among blastocyst transfers, DET was associated with very preterm birth (relative risk ratio, 2.64 [95% CI, 1.50-4.63]; ARD, 1.8 percentage points [95% CI, 0.3-3.4 percentage points]) and low birth weight (OR, 1.83 [95% CI, 1.29-2.60]; ARD, 3.2 percentage points [95% CI, 0.9-5.5 percentage points]).

Conclusions and Relevance

These results indicate a higher risk of adverse outcomes following DET, even when the result is a singleton birth, vs singletons born after SET. Adverse outcomes were mainly observed in singletons following DET using frozen embryos and blastocysts.

Single-embryo transfer implies quality of care in reproductive medicine

This review appraises evidence on the difference between single- and double-embryo transfer (SET, DET) in assisted reproductive technology (ART) regarding the four healthcare quality dimensions most important to fertility patients and doctors. Regarding safety, not only does DET create the uncontested perinatal risks of twin pregnancies, but compelling evidence has added that singleton pregnancies after a vanishing twin also have poorer perinatal outcomes. SET is as effective as DET, as shown by meta-analyses of randomized controlled trials, comparing two cycles of SET versus DET and shown by cumulative live birth rates of entire ART trajectories of up to six cycles. Proposing SET, which is safer than DET and as effective, as the gold standard is not irreconcilable with patient-centred care if patients are thoroughly informed on the reasoning behind the proposition and welcomed to challenge whether it fits their personal values. The cost-efficiency of SET is clearly higher, which has even induced certain countries to start reimbursing ART on the condition that SET is used. In conclusion, SET should be the gold standard offered to all patients. The question is not whether to apply SET but how to apply it in terms of patient selection, patient-centred counselling and coverage of treatment.

Nucleation status of Day 2 pre-implantation embryos, acquired by time-lapse imaging during IVF, is associated with live birth

The primary purpose of this time-lapse data analysis was to identify the association between the nucleation status of a Day 2 preimplantation embryo and live births following in vitro fertilization (IVF). The retrospective data analysis was based on 2769 transferred embryos from 1966 treatment cycles and utilised only Known Implantation Data (KID) for live births. Nucleation errors (NE) such as micronucleation, binucleation, multinucleation and minor error groups, were annotated in the time-lapse images which were taken every 15 minutes for a minimum of 44 hours post insemination. Further, factors that may impact NE and the relationship of early morphological attributes and morphokinetic variables with NE occurrence were explored. The frequency of NE among the transferred embryos was 23.8%. The reversibility of NE evidenced by their presence at the two-cell stage, but absence at the four-cell stage was 89.6%. Embryos exhibiting nucleation errors at the two-cell stage had significantly lower live birth rates compared to embryos with no nucleation errors, constituting a significant predictor. A Generalized Additive Mixed Model was used to control for confounders and for controlling clustering effects from dual embryo transfers. Increased incidences of NE were observed with increasing age, with delayed occurrence of cell divisions and in oocytes inseminated with surgically retrieved spermatozoa. NE assessment and their impact on live birth provides valuable markers for early preimplantation embryo selection. In addition, the high incidence of reversibility of NE and their possible impact on live birth suggest that incorporating two-cell nuclear status annotations in embryo selection, alongside morphology and morphokinetics, is of value.

The changing impact of assisted reproductive techniques on preterm birth during the period 2007-2020 in Lombardy, Northern Italy

OBJECTIVE

To assess the impact of Assisted Reproductive Techniques (ART) on the risk of preterm birth (PTB).

STUDY DESIGN

This retrospective population-based study used healthcare utilization databases of the Lombardy Region to select all the deliveries occurred between 2007 and 2020. Log-binomial regression models were fitted to estimate prevalence ratio (PR) and the corresponding 95% confidence interval (CI) of PTB among deliveries after ART. Estimates were adjusted for maternal sociodemographic features. Furthermore, the population attributable fraction was computed. All the analyses were performed for calendar period and were repeated excluding multiple births.

RESULTS

In our cohort, an increasing trend in the number of ART emerged, with an overall rate of 25.8 per 1,000 deliveries (N = 28,742). ART was positively related to PTB (aPR = 2.83, 95 % CI: 2.76-2.91) with a downward trend. Over the period study, multiple births after ART decreased (from 20.4 % to 8.4 %) and were constantly burdened by a higher number of PTB. Excluding multiple births, the association was substantially lower (aPR = 1.72, 95 % CI: 1.65-1.79) and did not describe any trend. Moreover, stratifying for type of pregnancy, the association was observed only among singletons. Finally, the proportion of PTB considered attributable to ART increased from about 2-3 % to 6 % till the 2016, then decreased.

CONCLUSION

The investigation suggested that ART was related to PTB; this association may be partly justified by the high rate of multiple births among women who conceived non spontaneously. However, excluding multiple births, ART remained associated with PTB.

Impact of co-transfer of embryos produced by somatic cell nuclear transfer using two types of donor cells on pregnancy outcomes in dogs

Objective

The present study analyzed the influence of co-transferring embryos with high and low cloning efficiencies produced via somatic cell nuclear transfer (SCNT) on pregnancy outcomes in dogs.

Methods

Cloned dogs were produced by SCNT using donor cells derived from a Tibetan Mastiff (TM) and Toy Poodle (TP). The in vivo developmental capacity of cloned embryos was evaluated. The pregnancy and parturition rates were determined following single transfer of 284 fused oocytes into 21 surrogates and co-transfer of 47 fused oocytes into four surrogates.

Results

When cloned embryos produced using a single type of donor cell were transferred into surrogates, the pregnancy and live birth rates were significantly higher following transfer of embryos produced using TP donor cells than following transfer of embryos produced using TM donor cells. Next, pregnancy and live birth rates were compared following single and co-transfer of these cloned embryos. The pregnancy and live birth rates were similar upon co-transfer of embryos and single transfer of embryos produced using TP donor cells but were significantly lower upon single transfer of embryos produced using TM donor cells. Furthermore, the parturition rate for TM dogs and the percentage of these dogs that remained alive until weaning was significantly higher upon co-transfer than upon single transfer of embryos. However, there was no difference between the two embryo transfer methods for TP dogs. The mean birth weight of cloned TM dogs was significantly higher upon single transfer than upon co-transfer of embryos. However, the body weight of TM dogs did not significantly differ between the two embryo transfer methods after day 5.

Conclusion

For cloned embryos with a lower developmental competence, the parturition rate and percentage of dogs that remain alive until weaning are increased when they are co-transferred with cloned embryos with a greater developmental competence.

Pregnancy outcome after in-vitro fertilization/intracytoplasmic sperm injection in women with congenital uterus didelphys

OBJECTIVE

To investigate the pregnancy and obstetric outcomes of patients with congenital uterus didelphys who achieved clinical pregnancy after in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

METHODS

This was a retrospective matched-cohort study of 83 infertile patients with uterus didelphys who underwent IVF/ICSI and achieved clinical pregnancy from January 2005 to December 2018 at our center. For each patient in the study group, three control patients with normal uterine morphology who underwent IVF/ICSI in 2018 were selected randomly. Patients in the two groups were matched for number of gestational sacs, maternal age, infertility type, cause of infertility, fertilization method, endometrial thickness 1 day before embryo transfer and number of embryos transferred. The classification of congenital uterine anomalies was based on the American Fertility Society system (1988). The pregnancy and obstetric outcomes of the didelphic and control groups were compared separately for singleton and twin pregnancies, and for all pregnancies combined.

RESULTS

In singleton pregnancies, women with uterus didelphys had increased risk of preterm birth (odds ratio (OR), 4.68; rate difference (RD), 0.14; P < 0.001), Cesarean section (OR, 2.80; RD, 0.17; P = 0.016) and birth weight < 2500 g (OR, 4.06; RD, 0.10; P = 0.017) compared to women with normal uterine morphology. In twin pregnancies, the presence of uterus didelphys was associated with increased risk of preterm delivery (OR, 4.79; RD, 0.37; P = 0.006), perinatal mortality (OR, 3.16; RD, 0.19; P = 0.043) and birth weight < 2500 g (OR, 9.57; RD, 0.35; P = 0.001).

CONCLUSIONS

The presence of uterus didelphys was associated with significantly increased risk of some adverse pregnancy outcomes compared to pregnancies with normal uterine morphology in women who underwent IVF/ICSI. A twin pregnancy in women with uterus didelphys was associated with worse perinatal outcome. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Noninvasive embryo evaluation and selection by time-lapse monitoring vs. conventional morphologic assessment in women undergoing in vitro fertilization/intracytoplasmic sperm injection: a single-center randomized controlled study

OBJECTIVE

To determine whether time-lapse monitoring (TLM) for cleavage-stage embryo selection improves reproductive outcomes in comparison with conventional morphological assessment (CMA) selection.

DESIGN

Prospective randomized controlled trial.

SETTING

Single academic center.

PATIENTS

We randomly assigned 139 women who were undergoing their first in vitro fertilization or intracytoplasmic sperm injection cycle to undergo either fresh embryo transfer or first frozen embryo transfer (FET). Only 1 cleavage-stage embryo was transferred to each participant.

INTERVENTIONS

The patients were randomly assigned to either the CMA or the TLM group. In the CMA group, day 2 and day 3 embryos were observed. A good-quality cleavage-stage embryo was selected for transfer or freezing in both groups.

MAIN OUTCOME MEASURES

The primary and secondary outcomes were the clinical pregnancy rate (CPR) and the live birth rate (LBR), respectively, after the first embryo transfer (fresh embryo transfer or FET).

RESULTS

The CPR and LBR were significantly lower in the TLM group than in the CMA group (CPR: 49.18% vs. 70.42%; relative risk, 0.70; 95% confidence interval [CI], 0.52-0.94; LBR: 45.90% vs. 64.79%; relative risk, 0.71; 95% CI, 0.51-0.98). The CPR with fresh embryo transfer or FET did not significantly differ between the TLM and the CMA groups (fresh embryo transfer: 44.44% vs. 70.0%, relative risk, 0.63, 95% CI, 0.39-1.03; FET: 52.94% vs. 70.73%, relative risk, 0.75, 95% CI, 0.52-1.09). There was a significant difference in the LBR with fresh embryo transfer between the TLM and the CMA groups (40.74% vs. 66.67%; relative risk, 0.61; 95% CI, 0.36-1.03). The LBRs with FET were similar in the TLM and the CMA groups (50.0% vs. 63.41%; relative risk, 0.79; 95% CI, 0.52-1.19). The rates of early spontaneous abortion and ectopic pregnancy did not differ between the TLM and the CMA groups.

CONCLUSIONS

Elective single cleavage-stage embryo transfer with TLM-based selection did not have any advantages over CMA when day 2 and day 3 embryo morphology was combined in young women with a good ovarian reserve. Because of these results, we conclude that TLM remains an investigational procedure for in vitro fertilization practice.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR1900021981.

Twinning in ART: Single embryo transfer policy

It is more than thirty years that perinatologists and healthcare personnel aim to reduce the morbidity associated with multiple pregnancy. In many cases, these complications stem from pregnancies achieved through artificial reproductive technologies (ART). Although dramatic measures have been taken to control those risks by increasing the proportion of single embryo transfers, the multiple pregnancy rate still remains relatively high among patient conceived through ART, carrying risks to both mothers and newborns, and is coupled with the related economic burden associated with prematurity. The aim of this review is to provide the current evidence regarding single embryo transfer to assist decision-makers and to promote patient knowledge toward an elective policy to reduce the risk of twinning. Single embryo transfer may aid in the further reduction of multiple pregnancy and, in most cases, will maintain patient autonomy and right of choice.

Non-Invasive Preimplantation Genetic Testing for Aneuploidy and the Mystery of Genetic Material: A Review Article

This review focuses on recent findings in the preimplantation genetic testing (PGT) of embryos. Different preimplantation genetic tests are presented along with different genetic materials and their analysis. Original material concerning preimplantation genetic testing for aneuploidy (PGT-A) was sourced by searching the PubMed and ScienceDirect databases in October and November 2021. The searches comprised keywords such as ‘preimplantation’, ‘cfDNA’; ‘miRNA’, ‘PGT-A’, ‘niPGT-A’, ‘aneuploidy’, ‘mosaicism’, ‘blastocyst biopsy’, ‘blastocentesis’, ‘blastocoel fluid’, ‘NGS’, ‘FISH’, and ‘aCGH’. Non-invasive PGT-A (niPGT-A) is a novel approach to the genetic analysis of embryos. The premise is that the genetic material in the spent embryo culture media (SECM) corresponds to the genetic material in the embryo cells. The limitations of niPGT-A are a lower quantity and lesser quality of the cell-free genetic material, and its unknown origin. The concordance rate varies when compared to invasive PGT-A. Some authors have also hypothesized that mosaicism and aneuploid cells are preferentially excluded from the embryo during early development. Cell-free genetic material is readily available in the spent embryo culture media, which provides an easier, more economic, and safer extraction of genetic material for analysis. The sampling of the SECM and DNA extraction and amplification must be optimized. The origin of the cell-free media, the percentage of apoptotic events, and the levels of DNA contamination are currently unknown; these topics need to be further investigated.

LC-MS Analysis Revealed the Significantly Different Metabolic Profiles in Spent Culture Media of Human Embryos with Distinct Morphology, Karyotype and Implantation Outcomes

In this study we evaluated possible differences in metabolomic profiles of spent embryo culture media (SECM) of human embryos with distinct morphology, karyotype, and implantation outcomes. A total of 153 samples from embryos of patients undergoing in vitro fertilization (IVF) programs were collected and analyzed by HPLC-MS. Metabolomic profiling and statistical analysis revealed clear clustering of day five SECM from embryos with different morphological classes and karyotype. Profiling of day five SECM from embryos with different implantation outcomes showed 241 significantly changed molecular ions in SECM of successfully implanted embryos. Separate analysis of paired SECM samples on days three and five revealed 46 and 29 molecular signatures respectively, significantly differing in culture media of embryos with a successful outcome. Pathway enrichment analysis suggests certain amino acids, vitamins, and lipid metabolic pathways to be crucial for embryo implantation. Differences between embryos with distinct implantation potential are detectable on the third and fifth day of cultivation that may allow the application of culture medium analysis in different transfer protocols for both fresh and cryopreserved embryos. A combination of traditional morphological criteria with metabolic profiling of SECM may increase implantation rates in assisted reproductive technology programs as well as improve our knowledge of the human embryo metabolism in the early stages of development.

Multiple gestation associated with infertility therapy: a committee opinion

This Committee Opinion provides practitioners with suggestions to reduce the likelihood of iatrogenic multiple gestation resulting from infertility treatment. This document replaces the document of the same name previously published in 2012 (Fertil Steril 2012;97:825-34 by the American Society for Reproductive Medicine).

Comparisons of benefits and risks of single embryo transfer versus double embryo transfer: a systematic review and meta-analysis

BACKGROUND

Evidence referring to the trade-offs between the benefits and risks of single embryo transfer (SET) versus double embryo transfer (DET) following assisted reproduction technology are insufficient, especially for those women with a defined embryo quality or advanced age.

METHODS

A systematic review and meta-analysis was conducted according to PRISMA guidelines. PubMed, EMBASE, Cochrane Library and ClinicalTrials.gov were searched based on established search strategy from inception through February 2021. Pre-specified primary outcomes were live birth rate (LBR) and multiple pregnancy rate (MPR). Odds ratio (OR) with 95% confidence interval (CI) were pooled by a random-effects model using R version 4.1.0.

RESULTS

Eighty-five studies (14 randomized controlled trials and 71 observational studies) were eligible. Compared with DET, SET decreased the probability of a live birth (OR = 0.78, 95% CI: 0.71-0.85, P < 0.001, n = 62), and lowered the rate of multiple pregnancy (0.05, 0.04-0.06, P < 0.001, n = 45). In the sub-analyses of age stratification, both the differences of LBR (0.87, 0.54-1.40, P = 0.565, n = 4) and MPR (0.34, 0.06-2.03, P = 0.236, n = 3) between SET and DET groups became insignificant in patients aged ≥40 years. No significant difference in LBR for single GQE versus two embryos of mixed quality [GQE + PQE (non-good quality embryo)] (0.99, 0.77-1.27, P = 0.915, n = 8), nor any difference of MPR in single PQE versus two PQEs (0.23, 0.04-1.49, P = 0.123, n = 6). Moreover, women who conceived through SET were associated with lower risks of poor outcomes, including cesarean section (0.64, 0.43-0.94), antepartum haemorrhage (0.35, 0.15-0.82), preterm birth (0.25, 0.21-0.30), low birth weight (0.20, 0.16-0.25), Apgar1 < 7 rate (0.12, 0.02-0.93) or neonatal intensive care unit admission (0.30, 0.14-0.66) than those following DET.

CONCLUSIONS

In women aged < 40 years or if any GQE is available, SET should be incorporated into clinical practice. While in the absence of GQEs, DET may be preferable. However, for elderly women aged ≥40 years, current evidence is not enough to recommend an appropriate number of embryo transfer. The findings need to be further confirmed.

Effectiveness and Safety of Two Consecutive Cycles of Single Embryo Transfer Compared With One Cycle of Double Embryo Transfer: A Systematic Review and Meta-Analysis

OBJECTIVE

To date, evidence regarding the effectiveness and safety of two consecutive cycles of single embryo transfer (2SETs) compared with one cycle of double embryo transfer (DET) has been inadequate, particularly considering infertile women with different prognostic factors. This study aimed to comprehensively summarize the evidence by comparing 2SETs with DET.

METHODS

PubMed, Embase, Cochrane Library databases, ClinicalTrails.gov, and the WHO International Clinical Trials Registry Platform were searched up to March 22, 2022. Peer-reviewed, English-language randomized controlled trials (RCTs) and observational studies (OS) comparing the outcomes of 2SETs with DET in infertile women with their own oocytes and embryos were included. Two authors independently conducted study selection, data extraction, and bias assessment. The Mantel-Haenszel random-effects model was used for pooling RCTs, and a Bayesian design-adjusted model was conducted to synthesize the results from both RCTs and OS.

MAIN RESULTS

Twelve studies were finally included. Compared with the DET, 2SETs were associated with a similar cumulative live birth rate (LBR; 48.24% vs. 48.91%; OR, 0.97; 95% credible interval (CrI), 0.89-1.13, τ^{2 =} 0.1796; four RCTs and six observational studies; 197,968 women) and a notable lower cumulative multiple birth rate (MBR; 0.87% vs. 17.72%; OR, 0.05; 95% CrI, 0.02-0.10, τ^{2 =} 0.1036; four RCTs and five observational studies; 197,804 women). Subgroup analyses revealed a significant increase in cumulative LBR (OR, 1.33; 95% CrI, 1.29-1.38, τ^{2 =} 0) after two consecutive cycles of single blastocyst transfer compared with one cycle of double blastocyst transfer. Moreover, a lower risk of cesarean section, antepartum hemorrhage, preterm birth, low birth weight, and neonatal intensive care unit admission but a higher gestational age at birth and birth weight were found in the 2SETs group.

CONCLUSION

Compared to the DET strategy, 2SETs result in a similar LBR while simultaneously reducing the MBR and improving maternal and neonatal adverse outcomes. The 2SETs strategy appears to be especially beneficial for women aged ≤35 years and for blastocyst transfers.

Fetal Reduction Could Improve but Not Completely Reverse the Pregnancy Outcomes of Multiple Pregnancies: Experience From a Single Center

OBJECTIVE

To investigate the effectiveness and limitations of multifetal pregnancy reduction (MFPR) on the improvement of pregnancy outcomes of triplet or twin pregnancies conceived by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

METHODS

We performed a cohort study of women undergoing IVF or ICSI from 2002-2016 in reproductive center, women's hospital, Zhejiang University School of Medicine. The cohort included 502 women who underwent MFPR and 9641 non-reduced women. Pregnancy outcomes were gestational age (GA) at delivery, pregnancy loss, preterm delivery, low birth weight (LBW), very low birth weight (VLBW), and small for gestational age (SGA). Multiple linear regression and logistic regression models were used to compare pregnancy outcomes between groups.

RESULTS

Triplets reduced to singletons had a longer median GA (39.07 vs 37.00, P<0.001), and lower rates of LBW (8.9% vs 53.2%, P<0.001) and SGA (17.8% vs 44.7%, P=0.001) than triplets reduced to twins, with a similar pregnancy loss rate (6.7% vs 6.6%, P=0.701). Twins reduced to singletons had a comparable pregnancy loss rate (4.8% vs. 6.5%, P=0.40), a longer median GA (38.79 vs. 37.00, P<0.001), and lower rates of LBW (13.5% vs. 47.0%, P<0.001) and SGA (13.5% vs. 39.6%, P<0.001) than primary twins. Triplets reduced to twins had higher rates of LBW (53.2% vs. 47.0%, P=0.028) and SGA (44.7% vs. 39.6%, P=0.040) than primary twins, with a similar pregnancy loss rate (6.6% vs. 6.5%, P=0.877). Singletons reduced from triplets/twins had higher rates of preterm delivery (15.8% vs. 7.3%, P<0.001), LBW (12.3% vs. 4.32%, P<0.001), VLBW (2.3% vs. 0.4%, P=0.002), and SGA (14.6% vs.6.6%, P<0.001) than primary singletons, with a comparable pregnancy loss rate (5.3% vs. 5.4%, P=0.671).

CONCLUSIONS

This study suggests that the pregnancy loss rate is similar between reduction and non-reduction groups. MFPR improves pregnancy outcomes, including the risk of preterm delivery, LBW, and SGA, but still could not completely reverse the adverse pregnancy outcomes of multiple pregnancies.

Morphometric and morphokinetic differences in the sperm- and oocyte-originated pronuclei of male and female human zygotes: a time-lapse study

PURPOSE

To study the morphometric and morphokinetic profiles of pronuclei (PN) between male and female human zygotes.

METHOD(S)

This retrospective cohort study included 94 consecutive autologous single day 5 transfer cycles leading to a singleton live birth. All oocytes were placed in the EmbryoScope + incubator post-sperm injection with all annotations performed retrospectively by one embryologist (L-SO). Timing parameters included 2nd polar body extrusion (tPB2), sperm-originated PN (tSPNa) or oocyte-originated PN (tOPNa) appearance, and PN fading (tPNF). Morphometrics were evaluated at 8 (stage 1), 4 (stage 2), and 0 h before PNF (stage 3), measuring PN area (um²), PN juxtaposition, and nucleolar precursor bodies (NPB) arrangement.

RESULTS

Male zygotes had longer time intervals of tPB2_tSPNa than female zygotes (4.8 ± 0.2 vs 4.2 ± 0.1 h, OR = 1.442, 95% CI 1.009-2.061, p = 0.044). SPN increased in size from stage 1 through 2 to 3 (435.3 ± 7.2, 506.7 ± 8.0, and 556.3 ± 8.9 um², p = 0.000) and OPN did similarly (399.0 ± 6.1, 464.3 ± 6.7, and 513.8 ± 6.5 um², p = 0.000), with SPN being significantly larger than OPN at each stage (p < 0.05 respectively). More male than female zygotes reached central PN juxtaposition at stage 1 (76.7% vs 51.0%, p = 0.010), stage 2 (97.7% vs 86.3%, p = 0.048), and stage 3 (97.7% vs 86.3%, p = 0.048). More OPN showed aligned NPBs than in SPN at stage 1 only (44.7% vs 28.7%, p = 0.023).

CONCLUSION(S)

Embryos with different sexes display different morphokinetic and morphometric features at the zygotic stage. Embryo selection using such parameters may lead to unbalanced sex ratio in resulting offspring.

Clinical outcomes for Day 3 double cleavage-stage embryo transfers versus Day 5 or 6 single blastocyst transfer in frozen-thawed cycles: a retrospective comparative analysis

Objective

This study aimed to compare the clinical outcomes for transfer of Day 3 (D3) double cleavage-stage embryos and Day 5/6 (D5/6) single blastocysts in the frozen embryo transfer (FET) cycle to formulate a more appropriate embryo transplantation strategy.

Methods

We retrospectively analyzed 609 FET cycles from 518 women from April 2017 to March 2021. All FETs were assigned to the D3-DET group (transfer of a Day 3 double cleavage-stage embryo), D5-SBT group (transfer of a Day 5 single blastocyst), or D6-SBT group (transfer of a Day 6 single blastocyst). Clinical outcomes were comparatively analyzed.

Results

There were no significant differences in the biochemical pregnancy rate, clinical pregnancy rate, or ongoing pregnancy rate between the D3-DET and D5-SBT groups, but these rates in the two groups were all significantly higher compared with those in the D6-SBT group. The implantation rate in the D5-SBT group was significantly higher than that in the D3-DET group. The twin pregnancy rate in the D5-SBT and D6-SBT groups was significantly lower than that in the D3-DET group.

Conclusion

This study suggests that D5-SBT is the preferred option for transplantation. D6-SBT reduces the pregnancy rate, making it a more cautious choice for transfer of such embryos.

Single blastocyst stage versus single cleavage stage embryo transfer following fresh transfer: A systematic review and meta-analysis

OBJECTIVES

To compare the available evidence of the effectiveness of single blastocyst stage transfer against the effectiveness of single cleavage stage embryo transfer.

STUDY DESIGN

A systematic research based on Pubmed, Embase and the Cochrane Library was performed until May 2, 2020 to identify all relevant studies. The Cochrane Collaboration's Review Manager (RevMan) 5.0.2 software was used for statistical analysis.

RESULTS

Five randomized controlled trials (RCTs) were included in analysis, involving 1784 patients in total, who were divided into 2 groups, which were the single blastocyst stage transfer (SBT) group of 932, and the single cleavage stage transfer (SCT) group of 852. Our meta-analysis concluded that SBT group had a significantly higher clinical pregnancy rate (RR 1.26; 95%CI: 1.14-1.39), ongoing pregnancy rate (RR 1.19; 95%CI: 1.05-1.35) and delivery rate (RR 1.4; 95%CI: 1.13-1.75) than SCT group during the fresh transfer. While miscarriage rate (RR 0.93; 95% CI: 0.66-1.33), multiple pregnancy rate (RR, 1.12; 95% CI, 0.51-2.45) and ectopic pregnancy rate (RR, 0.5; 95% CI: 0.13-1.90) between two groups showed no significant difference. However, the SCT group contained notably more cryopreserved embryos than the SBT group. (RR -0.68, 95% CI: -0.95 to -0.41).

CONCLUSIONS

Our results indicate that single blastocyst stage transfer is associated with higher ongoing pregnancy rate and delivery rate comparing to single cleavage stage transfer in the clinical practice. Due to the low quality of the evidence of the primary outcomes, other higher-quality lager RCTs are necessary before a fully informed decision is made.

PGT-A: who and when? Α systematic review and network meta-analysis of RCTs

PURPOSE

Wide controversy is still ongoing regarding efficiency of preimplantation genetic testing for aneuploidy (PGT-A). This systematic review and meta-analysis, aims to identify the patient age group that benefits from PGT-A and the best day to biopsy.

METHODS

A systematic search of the literature was performed on MEDLINE/PubMed, Embase and Cochrane Central Library up to May 2020. Eleven randomized controlled trials employing PGT-A with comprehensive chromosomal screening (CCS) on Day-3 or Day-5 were eligible.

RESULTS

PGT-A did not improve live-birth rates (LBR) per patient in the general population (RR:1.11; 95%CI:0.87-1.42; n=1513; I2=75%). However, PGT-A lowered miscarriage rate in the general population (RR:0.45; 95%CI:0.25-0.80; n=912; I2=49%). Interestingly, the cumulative LBR per patient was improved by PGT-A (RR:1.36; 95%CI:1.13-1.64; n=580; I2=12%). When performing an age-subgroup analysis PGT-A improved LBR in women over the age of 35 (RR:1.29; 95%CI:1.05-1.60; n=692; I2=0%), whereas it appeared to be ineffective in younger women (RR:0.92; 95%CI:0.62-1.39; n=666; I2=75%). Regarding optimal timing, only day-5 biopsy practice presented with improved LBR per ET (RR: 1.37; 95% CI: 1.03-1.82; I2=72%).

CONCLUSION

PGT-A did not improve clinical outcomes for the general population, however PGT-A improved live-birth rates strictly when performed on blastocyst stage embryos of women over the 35-year-old mark.

Time associations between U.S. birth rates and add-Ons to IVF practice between 2005-2016

Until 2010, the National Assisted Reproductive Technology Surveillance System (NASS) report, published annually by the Center for Disease Control and Prevention (CDC), demonstrated almost constantly improving live birth rates following fresh non-donor (fnd) in vitro fertilization (IVF) cycles. Almost unnoticed by profession and public, by 2016 they, however, reached lows not seen since 1996-1997. We here attempted to understand underlying causes for this decline. This study used publicly available IVF outcome data, reported by the CDC annually under Congressional mandate, involving over 90% of U.S. IVF centers and over 95% of U.S. IVF cycles. Years 2005, 2010, 2015 and 2016 served as index years, representing respectively, 27,047, 30,425, 21,771 and 19,137 live births in fnd IVF cycles. Concomitantly, the study associated timelines for introduction of new add-ons to IVF practice with changes in outcomes of fnd IVF cycles. Median female age remained at 36.0 years during the study period and center participation was surprisingly stable, thereby confirming reasonable phenotype stability. Main outcome measures were associations of specific IVF practice changes with declines in live IVF birth rates. Time associations were observed with increased utilization of "all-freeze" cycles (embryo banking), mild ovarian stimulation protocols, preimplantation genetic testing for aneuploidy (PGT-A) and increasing utilization of elective single embryo transfer (eSET). Among all add-ons, PGT-A, likely, affected fndIVF most profoundly. Though associations cannot denote causation, they can be hypothesis-generating. Here presented time-associations are compelling, though some of observed pregnancy and live birth loss may have been compensated by increases in frozen-thawed cycles and consequential pregnancies and live births not shown here. Pregnancies in frozen-thawed cycles, however, represent additional treatment cycles, time delays and additional costs. IVF live birth rates not seen since 1996-1997, and a likely continuous downward trend in U.S. IVF outcomes, therefore, mandate a reversal of current outcome trends, whatever ultimately the causes.

Multiple Gestations and Assisted Reproductive Technologies: Qualitative Study of the Discourse of Health Professionals in Spain

Multiple gestations have become an increasing phenomenon that has impacted public health globally, largely due to the application of assisted reproductive technologies. The objective of this work was to find out the discourse that the health professionals involved in its follow-up have in our context. For this, a qualitative methodology was chosen, with semi-structured interviews recorded in audio, prior authorisation, and transcribed verbatim. It was based on a script designed for this purpose, with the following analysis categories: the current trend of multiple gestations, impact, and follow-up. The content analysis was based on the experiences, knowledge, and perceptions of the professionals interviewed. Professionals stated that the current socioeconomic and legal context hinders a single embryo transfer policy that decreases multiple gestation rates. They emphasised the importance of the psychic impact of such gestations on the couple, on the mother in particular, as well as the economic effect on families, health, and society in general. They expressed the need to create specific protocols to assist these gestations. Midwives, in particular, demanded that the health administration recognise and support the differentiated care they perform with this type of gestation. Work on specific models is needed to adequately size the impact of multiple gestations, as well as to generate social health policies that lead to co-responsible reconciliation measures that favour women having one pregnancy at a time.

Does fresh or frozen embryo transfer affect imprinted gene expressions in human term placenta?

Our research aimed to compare the epigenetic alterations between placentae of in vitro fertilization (IVF) patients and spontaneous pregnancies. Additionally, the expression levels of proliferation markers (PCNA, Ki67) and glucose transporter proteins (GLUT1, GLUT3) were assessed in control and IVF placentae to examine the possible consequences of epigenetic alterations on placental development. Control group placentae were obtained from spontaneous pregnancies of healthy women (n = 16). IVF placentae were obtained from fresh (n = 16) and frozen (n = 16) embryo transfer pregnancies. A group of maternal and paternal imprint genes H19, IGF2, IGF2, IGF2R, PHLDA2, PLAGL1, MASH2, GRB10, PEG1, PEG3, and PEG10 were detected by Real-Time PCR. Additionally, PCNA, Ki67, GLUT1, and GLUT3 protein levels were assessed by immunohistochemistry and western blot. In the fresh embryo transfer placenta group (fETP), gene expression of paternal PEG1 and PEG10 was upregulated compared with the control group. Increased gene expression in paternal PEG1 and maternal IGFR2 genes was detected in the frozen embryo transfer placenta group (FET) compared with the control group. Conversely, expression levels of H19 and IGF2 genes were downregulated in the FET group. On the other hand, GLUT3 and PCNA expression was increased in FET group placentae. IVF techniques affect placental imprinted gene expressions which are important for proper placental development. Imprinted genes are differently expressed in fresh ET placentae and frozen ET placentae. In conclusion, these data indicate that altered imprinted gene expression may affect glucose transport and cell proliferation, therefore play an important role in placental development.

Fertility technologies and how to optimize laboratory performance to support the shortening of time to birth of a healthy singleton: a Delphi consensus

PURPOSE

To explore how the assisted reproductive technology (ART) laboratories can be optimized and standardized to enhance embryo culture and selection, to bridge the gap between standard practice and the new concept of shortening time to healthy singleton birth.

METHODS

A Delphi consensus was conducted (January to July 2018) to assess how the ART laboratory could be optimized, in conjunction with existing guidelines, to reduce the time to a healthy singleton birth. Eight experts plus the coordinator discussed and refined statements proposed by the coordinator. The statements were distributed via an online survey to 29 participants (including the eight experts from step 1), who voted on their agreement/disagreement with each statement. Consensus was reached if ≥ 66% of participants agreed/disagreed with a statement. If consensus was not achieved for any statement, that statement was revised and the process repeated until consensus was achieved. Details of statements achieving consensus were communicated to the participants.

RESULTS

Consensus was achieved for all 13 statements, which underlined the need for professional guidelines and standardization of lab processes to increase laboratory competency and quality. The most important points identified were the improvement of embryo culture and embryo assessment to shorten time to live birth through the availability of more high-quality embryos, priority selection of the most viable embryos and improved cryosurvival.

CONCLUSION

The efficiency of the ART laboratory can be improved through professional guidelines on standardized practices and optimized embryo culture environment, assessment, selection and cryopreservation methodologies, thereby reducing the time to a healthy singleton delivery.

Adding a low-quality blastocyst to a high-quality blastocyst for a double embryo transfer does not decrease pregnancy and live birth rate

INTRODUCTION

The effect of embryo quality on clinical outcomes of assisted reproductive technology following a double transfer is not well defined, with some studies suggesting that a low-quality embryo transferred with a high-quality embryo decreases the live birth rate (LBR), compared with transferring a single high-quality embryo. Our study examined whether the quality of a second blastocyst transferred affects the outcome, controlling for the number of the available high-quality blastocysts (HQB).

MATERIAL AND METHODS

A historical cohort study of 2346 fresh blastocyst transfers in a single fertility clinic between 2013 and 2019. The main outcomes were pregnancy, miscarriage, live birth, and multiple gestation rates. Outcomes were compared between single embryo transfers with a high-quality blastocyst (SET-H), double embryo transfers with two HQBs (DET-HH), and transfers with one high-quality and one low-quality blastocyst (DET-HL). Outcomes were also assessed between SET and DET when only low-quality blastocysts were available.

RESULTS

With one HQB available, DET-HL increased LBR (adjusted odds ratio [OR] 1.65, 95% CI 1.09-2.49) compared with SET-H, but increased multiple gestation rate (aOR 23.1, 95% CI 3.0-177.6). With two HQBs available, DET-HH was associated with a higher LBR (aOR 1.62, 95% CI 1.28-2.04) and lower miscarriage rate (aOR 0.56, 95% CI 0.40-0.80), but very high twin rate (aOR 49.8, 95% CI 24.3-102.1) compared with SET-H. A SET-H with at least one or more HQB available to freeze, compared with a SET-H with no other HQB available, had a higher LBR (aOR 1.69, 95% CI 1.17-2.45). When there were no HQBs available, compared with SET-L, a DET-LL had a higher live birth (aOR 3.20, 95% CI 1.78-7.703) and twin rate (aOR 3.72 × 10¹⁰ ) and a lower miscarriage rate (aOR 0.24, 95% CI 0.10-0.58).

CONCLUSIONS

When there is one HQB available, transferring an additional low-quality blastocyst would only slightly increase the LBR, but significantly increase the twin rate, therefore SET should be recommended. When two or more HQBs are available, SET-H would have a reasonably good chance of success without the very high twin rate associated with DET-HH. DET-LL when compared with SET-L, would increase the LBR, but increase the risk of multiple gestation.

Monozygotic dichorionic-diamniotic twin pregnancy after single embryo transfer at blastocyst stage: a case report

Single embryo transfer is highly encouraged on in vitro fertilization due to its lower rates of multiple pregnancy. Nevertheless, the likelihood of multiple pregnancy is higher when using assisted reproductive technology, probably because of embryo handling. Timing is crucial in the post-fertilization division of a single embryo to establish the amniocity and chorionicity of the gestation. In the case reported a 38 year-old woman, nulligravid, had a single blastocyst implanted, which resulted in monozygotic dichorionic-diamniotic twins. Despite being rare, there are reports of similar cases questioning the current knowledge on time of embryo division and the impact of assisted reproduction.

Effect of Age and Morphology on Live Birth Rate After Cleavage Stage Embryo Transfer

Accurate knowledge of the live birth rate for cleavage stage embryos is essential to determine an appropriate number of embryos to transfer at once. Results from previous studies lack details needed for practical use. This is a mathematical analysis and model building study of day 3 cleavage stage embryo transfers. A total of 996 embryos were transferred in 274 fresh and 83 frozen embryo transfers. Embryo morphology was divided into 4 groups based on number of cells and fragmentation percentage. Each embryo transfer was modeled as an equation equating the sum of the live birth rates of the transferred embryos to the number of live births that resulted. The least squares solution to the system of embryo transfer equations was determined using linear algebra. This analysis was repeated for ages 35 to 42 years old at oocyte retrieval. The best fit live birth rates per embryo in the age group centered on 35 years old were 29%, 13%, 10%, and 9% for embryos in the 8-cell with ≤ 5% fragmentation, 8-cell with > 5% fragmentation, 9-12 cell, and 6-7 cell groups, respectively. Cleavage stage embryos with fewer than 6 cells on day 3 had very low best fit live birth rates close to 0% at age 39 years and were excluded from the primary analysis to prevent overfitting. These live birth rates can be used with a simple embryo transfer model to predict rates of single and multiple gestation prior to a planned cleavage stage embryo transfer.

What Are the Live Birth and Multiple Pregnancy Rates When 1 Versus 2 Low-Quality Blastocysts Are Transferred in a Cryopreserved Cycle? a Retrospective Cohort Study, Stratified for Age, Embryo Quality, and Oocyte Donor Cycles

Outcomes among women who transferred only Gardner's grade BB or lower quality frozen embryos transferred (FET) are not well known. Our objective is to study whether transferring 2 versus 1 frozen low-quality blastocysts will increase the live birth rate (LBR) and the multiple pregnancy rate (MPR). This is a retrospective cohort study including 1104 FET cycles. Only day 5-6 blastocysts of grade BB or lower quality were included. Clinical pregnancy rate (CPR), MPR, and LBR per cycle were compared between single embryo transfer (SET) (n = 969) and double embryo transfer (DET) (n = 135). CPR and MPR were compared between SET and DET in grade BB, BC, CB, and CC individually. Among SET, BB blastocysts had higher CPR 34% (P = 0.0001) and a sub-significant increase in LBR 19% (P = 0.059) in comparison to other grade SET. Among all BB, MPR was significantly higher when transferring two versus one (5.9 vs. 1.9, P = 0.009). If age at egg collection ≥ 40 years (n = 97), no difference was found in CPR (11.1 vs. 11.7, P = 0.9), MPR (0 vs. 0), and LBR (6.3 vs. 0,P = 0.13) when SET or DET was performed. If age was < 40 years (n = 818), the MPR was significantly higher in DET than SET (6.7 vs. 1.63, P = 0.004). In egg donor cycles (n = 189), there was no difference in CPR, MPR, and LBR between SET and DET. Single embryo transfer should be offered even in women ≥ 40 years of age or transferring lower quality embryos since transferring more did not increase outcomes in this group, and SET is likely the safest path.