Vitrified blastocyst transfer cycles with the use of only vaginal progesterone replacement with Endometrin have inferior ongoing pregnancy rates: results from the planned interim analysis of a three-arm randomized controlled noninferiority trial

Ovulation-induced frozen embryo transfer regimens in women with polycystic ovary syndrome: a systematic review and meta-analysis

PURPOSE

To evaluate whether the type of frozen embryo transfer (FET) regimen - ovulation-induced regimens vs. hormone replacement therapy regimens (HRT) - is associated with live birth rates and the risk of hypertensive diseases of pregnancy (HDP) in women with polycystic ovary syndrome (PCOS).

METHODS

All studies in PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched using a combination of MeSH terms and keywords. Inclusion criteria included studies on women with a diagnosis of PCOS, utilization of FET, and reporting of pregnancy and/or obstetric outcomes. Studies were excluded if they were case series or conference abstracts or used other FET regimens. A random effects meta-analysis was performed. Primary outcomes include relative risk (RR) of live birth and HDP.

RESULTS

Eleven studies were included in the meta-analysis for the final review. Ovulation-induced regimens were associated with a higher live birth rate (8 studies, RR 1.14 [95% CI 1.08, 1.21]) compared to HRT regimens. The risk of HDP (3 studies RR 0.78 [95% CI 0.53, 1.15]) was not significantly different. Ovulation-induced regimens were associated with a lower miscarriage rate (9 studies, RR 0.67 [95% CI 0.59-0.76]). Rates of clinical pregnancy (10 studies, RR 1.05 [95% CI 0.99, 1.11]) and ectopic pregnancy (7 studies, RR 1.40 [95% CI 0.84, 2.33]), were not significantly different.

CONCLUSION

This SR/MA demonstrates that for women with PCOS, ovulation-induced FET regimens are associated with higher rates of live birth and lower rates of miscarriage compared to HRT regimens.

Lower Pregnancy and Live Birth Rates with Vaginal Endometrin Plus Intramuscular Progesterone Every Third Day Versus Intramuscular Progesterone Alone in Programmed Frozen Embryo Transfers: A Retrospective Case-control Study

This study aimed to determine whether the use of vaginal Endometrin plus intramuscular progesterone on every third day (VIM) in programmed frozen embryo transfer (FET) is associated with lower pregnancy and live birth rates compared to daily intramuscular progesterone (IM). FET data from a single program were collected between November 2018 and December 2021. A total of 903 FETs were analyzed, including 504 FETs in the IM group, and 399 FETs in the VIM group. Inclusion criteria were women undergoing FETs with either 50 mg daily IM progesterone only (control) or 200 mg Endometrin twice daily plus 50 mg IM progesterone on every third day, with the transfer of a single day 5 or 6 frozen embryo. There were no significant differences in patient age at time of FETs, BMI, endometrial thickness, blastocyst quality, or infertility diagnosis between the groups. The VIM had significantly lower positive hCG and clinical pregnancy rates compared to the IM (60.2% vs 72.0% and 40.6% vs 56.7%, respectively, P = 0.0002 and P < 0.0001). The live birth rate was 36.1% in the VIM, compared to 49.4% in the IM (P < 0.0001). These findings also remained significant when excluding FETs with donor egg (35.9% vs 50.1%, P < 0.0001). This study demonstrated that VIM in FET cycles yields significantly lower pregnancy and live birth rates compared to IM along. IM progesterone alone may be preferable to combined Endometrin and IM progesterone in patients undergoing programmed frozen embryo transfers.

The Impact of Progesterone Administration Routes on Endometrial Receptivity and Clinical Outcomes in Assisted Reproductive Technology Cycles

Introduction Assisted reproductive technologies (ART) rely on endometrial receptivity (ER) for successful embryo implantation. This study aimed to compare the impact of different progesterone administration routes on ER assessed using optimal time for endometrial receptivity analysis (OpERA) and clinical outcomes in ART cycles. Methods A retrospective cohort analysis was conducted on 281 infertile women who underwent in vitro fertilization (IVF). Patients were stratified based on progesterone administration routes: oral and vaginal progesterone (Group 1) vs. intramuscular progesterone (Group 2). OpERA was performed on 257 patients to assess ER. Clinical outcomes, including biochemical pregnancy rate (BPR), clinical pregnancy rate (CPR), implantation rate (IR), and abortion rate (AR), were compared between the groups. Results OpERA results showed no significant differences between Group 1 and Group 2 in receptive (51.2% vs. 52.0%, p = 0.857), pre-receptive (44.1% vs. 44.6%, p = 0.933), or post-receptive (4.7% vs. 3.1%, p = 0.496) states. Clinical outcomes, including BPR (59.9% vs. 60.9%, p = 0.903), CPR (50.0% vs. 56.5%, p = 0.463), IR (52.5% vs. 55.3%, p = 0.748), and AR (44.3% vs. 45.6%, p = 0.882), did not significantly differ between the groups. Conclusion Progesterone administration routes did not significantly affect ER or clinical outcomes, highlighting the need to prioritize understanding and enhancing ER instead of solely focusing on progesterone delivery methods. Identifying molecular pathways or biomarkers could improve receptivity and optimize ART, ultimately improving pregnancy outcomes.

Luteal phase support in assisted reproductive technology

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

Comparative Bioavailability of Two Daily Subcutaneous Doses Versus a Single Dose of Intramuscular and Vaginal Progesterone Formulations in Healthy Postmenopausal Females

Progesterone is a naturally occurring endocrine hormone. It is used for luteal phase support to improve success rates in assisted reproduction. This was a single-center, comparative bioavailability, open-label, randomized, 3-period, 6-sequence, crossover study to compare the rate and extent of absorption of subcutaneous (SC) progesterone 25 mg twice daily, versus vaginal (Vag) gel once daily (90 mg progesterone) and 50 mg of intramuscular (IM) progesterone injection once daily in healthy postmenopausal females. Eighteen healthy, postmenopausal, female nonsmokers aged 55-65 years were dosed. Data from 17 subjects who completed at least 2 study periods, including the test and 1 reference, were included in the pharmacokinetic analysis. The SC progesterone product administered twice daily showed a higher exposure than a single dose of the Vag formulation, with least-squares mean (LSM) ratios (SC/Vag gel) of 219.7% for AUC0-inf and 391.8% for Cmax . The SC progesterone product administered twice daily showed comparable extent of exposure to that of the IM product, but showed higher peak concentration, with LSM ratios (SC/IM) of 92.4% for AUC0-inf and 138.0% for Cmax . Mean (SD) relative bioavailability (Frel ) for SC/Vag gel was 449.6 (233.1)%, and for SC/IM was 92.3 (6.3)%. Mild injection site reactions were reported with similar frequency for SC and IM progesterone. With further research, twice-daily SC progesterone may offer an alternative to existing available treatments for luteal phase support.

Finding of the optimal preparation and timing of endometrium in frozen-thawed embryo transfer: a literature review of clinical evidence

Frozen-thawed embryo transfer (FET) has been a viable alternative to fresh embryo transfer in recent years because of the improvement in vitrification methods. Laboratory-based studies indicate that complex molecular and morphological changes in endometrium during the window of implantation after exogenous hormones with controlled ovarian stimulation may alter the interaction between the embryo and endometrium, leading to a decreased implantation potential. Based on the results obtained from randomized controlled studies, increased pregnancy rates and better perinatal outcomes have been reported following FET. Compared to fresh embryo transfer, fewer preterm deliveries, and reduced incidence of ovarian hyperstimulation syndrome were found after FETs, yet there is a trend of increased pregnancy-related hypertensive diseases in women receiving FET. Despite the increased application of FET, the search for the most optimal priming protocol for the endometrium is still undergoing. Three available FET protocols have been proposed to prepare the endometrium: i) natural cycle (true natural cycle and modified natural cycle) ii) artificial cycle (AC) or hormone replacement treatment cycle iii) mild ovarian stimulation (mild-OS) cycle. Emerging evidence suggests that the optimal timing for FET using warmed blastocyst transfer is the LH surge+6 day, hCG administration+7 day, and the progesterone administration+6 day in the true natural cycle, modified natural cycle, and AC protocol, respectively. Although still controversial, better clinical pregnancy rates and live birth rates have been reported using the natural cycle (true natural cycle/modified natural cycle) compared with the AC protocol. Additionally, a higher early pregnancy loss rate and an increased incidence of gestational hypertension have been found in FETs using the AC protocol because of the lack of a corpus luteum. Although the common clinical practice is to employ luteal phase support (LPS) in natural cycles and mild-OS cycles for FET, the requirement for LPS in these protocols remains equivocal. Recent findings obtained from RCTs do not support the routine application of endometrial receptivity testing to optimize the timing of FET. More RCTs with rigorous methodology are needed to compare different protocols to prime the endometrium for FET, focusing not only on live birth rate, but also on maternal, obstetrical, and neonatal outcomes.

The optimal route of progesterone administration for luteal phase support in a frozen embryo transfer: a systematic review

OBJECTIVE

To investigate the optimal route of progesterone administration for luteal phase support in a frozen embryo transfer.

DESIGN

Systematic review.

PATIENTS

Women undergoing frozen embryo transfer (FET).

INTERVENTIONS

We conducted an extensive database search of Medline (PubMed), Embase, Web of Science, and Cochrane Trials Register using relevant keywords and their combinations to find randomized controlled trials (RCTs) comparing the routes (i.e., oral, vaginal, intramuscular) of progesterone administration for luteal phase support (LPS) in artificial FET.

MAIN OUTCOME MEASURES

Clinical pregnancy, live birth, miscarriage.

RESULTS

Four RCTs with 3245 participants undergoing artificial endometrial preparation (EP) cycles during FET were found to be eligible. Four trials compared vaginal progesterone with intramuscular progesterone and two trials compared vaginal progesterone with oral progesterone. One study favored of vaginal versus oral progesterone for clinical pregnancy rates (RR 0.45, 95% CI 0.22-0.92) and other study favored intramuscular versus vaginal progesterone for clinical pregnancy rates (RR 1.46, 95% CI 1.21-1.76) and live birth rates (RR 1.62, 95% CI 1.28-2.05). Tabulation of overall evidence strength assessment showed low-quality evidence on the basis that for each outcome-comparison pair, there were deficiencies in either directness of outcome measurement or study quality.

CONCLUSION

There was little consensus and evidence was heterogeneous on the optimal route of administration of progesterone for LPS during FET in artificial EP cycles. This warrants more trials, indirect comparisons, and network meta-analyses.

PROPERO NO

CRD42021251017.

The association between the type of progesterone supplementation and miscarriage risk in women who have had a positive pregnancy test following embryo transfer: a retrospective cohort study

PURPOSE

The purpose of this study was to identify if switching from intramuscular (IM) to vaginal progesterone compared to staying on IM progesterone after a positive pregnancy test following embryo transfer (ET) is associated with miscarriage risk.

METHODS

A retrospective cohort study was performed in a private university-affiliated fertility clinic and included women aged 18-50 years with a positive pregnancy test following ET. The two groups studied were: women who stayed on IM progesterone following a positive pregnancy test and those who switched to vaginal progesterone after a positive test. The main outcome measured was risk of miscarriage < 24 weeks gestation as a proportion of non-biochemical pregnancies.

RESULTS

1988 women were included in the analysis. Among the baseline characteristics, the presence of prior miscarriages as well as prior failed ETs, and frozen cycles (vs fresh) as type of transfer were associated with IM progesterone use (p values ≤ 0.01). As per miscarriage risk < 24 weeks, 22.4% (274/1221) of patients in the IM progesterone group experienced a miscarriage compared with 20.7% (159/767) in the vaginal progesterone group (OR 0.90; 95% CI 0.73-1.13). A multivariable logistic regression model revealed an adjusted OR (aOR) of 0.97 (95% CI 0.77-1.22).

CONCLUSION

This study suggests that switching from IM to vaginal progesterone after a positive pregnancy test following an ET is not associated with miscarriage risk. Considering that IM progesterone imposes substantial discomfort, this study offers reassurance and some flexibility in treatment protocols. Further prospective studies are necessary to corroborate the results of this study.

Preparation of the endometrium for frozen embryo transfer: an update on clinical practices

Over the past decade, the application of frozen-thawed embryo transfer treatment cycles has increased substantially. Hormone replacement therapy and the natural cycle are two popular methods for preparing the endometrium. Hormone replacement therapy is now used at the discretion of the doctors because it is easy to coordinate the timing of embryo thawing and transfer with the schedules of the in-vitro fertilization lab, the treating doctors, and the patient. However, current results suggest that establishing a pregnancy in the absence of a corpus luteum as a result of anovulation may pose significant maternal and fetal risks. Therefore, a 'back to nature' approach that advocates an expanded use of natural cycle FET in ovulatory women has been suggested. Currently, there is increasing interest in how the method of endometrial preparation may influence frozen embryo transfer outcomes specifically, especially when it comes to details such as different types of ovulation monitoring and different luteal support in natural cycles, and the ideal exogenous hormone administration route as well as the endocrine monitoring in hormone replacement cycles. In addition to improving implantation rates and ensuring the safety of the fetus, addressing these points will allow for individualized endometrial preparation, also as few cycles as possible would be canceled.

Association between serum progesterone levels on the day of frozen-thawed embryo transfer and pregnancy outcomes after artificial endometrial preparation

BACKGROUND

Previous studies have examined that a range of optimal serum P level during the implantation period was associated with optimal live birth rates. However, those results obtained with vaginal or intramuscular route of progesterone administration for luteal phase support (LPS) alone. Is there a relationship between the serum progesterone (P) on the day of frozen-thawed embryo transfer (FET) with the likelihood of a live birth (LB) in artificial cycles (AC) when using a combination of oral dydrogesterone and vaginal progesterone for LPS?

METHODS

This was a retrospective study of 3659 FET cycles with artificial endometrial preparation in a Chinese tertiary-care academic medical centre from January 2015 to February 2017. Endometrial preparation was performed using estradiol (E₂) valerate (Fematon-red tablets) 8 mg/d beginning on day 3 of the cycle, followed by administration of P both orally (8 mg/d Fematon-yellow tablets) and vaginally (400 mg/d; Utrogestan). The primary endpoint was live birth rate (LBR). The association between the serum P level on the embryo transfer day and pregnancy outcomes was evaluated by univariable and multivariable logistic regression analysis.

RESULTS

The LBRs according to the serum P quartiles were as follows: Q1: 35.7%; Q2: 37.4%; Q3: 39.1% and Q4: 38.9%. Logistic regression analysis showed that the odds of a LB were not significantly different between the low (P < 7.9 ng/mL) and high (P ≥ 7.9 ng/mL) progesterone groups before or after adjustment (crude OR = 0.89, 95% CI: 0.76-1.04; adjusted OR = 0.89, 95% CI: 0.75-1.04).

CONCLUSION

The present study suggests that the serum P levels on the day of embryo transfer (ET) do not correlate with the likelihood of a LB in artificial cycles when using a combination of oral dydrogesterone and vaginal progesterone for luteal phase support.

Effects of two different types of luteal support on pregnancy outcomes following antagonist fresh embryo transfer: a retrospective study

BACKGROUND

Only a small number of studies have reported the use of progesterone vaginal gel in combination with dydrogesterone as part of the antagonist protocol for fresh embryo transfer. Therefore, this study aimed to compare the effects of two types of luteal support on pregnancy outcomes following the antagonist protocol for fresh embryo transfer.

METHODS

We performed a retrospective analysis of clinical data from infertile patients who underwent fresh embryo transfer via the antagonist protocol (2785 cycles) between February and July 2019 and between February and July 2021 at the Peking University Third Hospital Reproductive Medicine Centre. According to the luteal support received, the cycle groups were divided into the progesterone vaginal gel group (single medication or VP group; 1170 cycles) and the progesterone vaginal gel plus dydrogesterone group (combination medication or DYD + VP group; 1615 cycles). After propensity score matching, the clinical pregnancy, ongoing pregnancy, early miscarriage, and ectopic pregnancy rates were compared between the two groups.

RESULTS

In total, 1057 pairs of cycles were successfully matched via propensity scores. The clinical and ongoing pregnancy rates in the combination medication group were significantly higher than those in the single medication group (P < 0.05), whereas no significant differences were noted in the early miscarriage and ectopic pregnancy rates between the two groups (both P > 0.05).

CONCLUSIONS

Combined luteal support after the antagonist protocol is preferred for patients undergoing fresh cycle embryo transfer.

Serum progesterone level in luteal phase improves pregnancy rate in fresh cycles with blastocyst embryo transfer

OBJECTIVE

To assess the association between serum level of progesterone during stimulation and in the luteal phase with pregnancy rate in a cohort of patients undergoing in vitro fertilization and embryo transfer (IVF-ET) on day 5.

METHODS

Retrospective Cohort Study. Patients: 62 infertile women, aged 24-42 years, undergoing ART at our center from May 2019 to May 2021. Progesterone was evaluated during ovarian stimulation on Day 2, Day 6, and Day 8 of stimulation, day of trigger (P4dhCG), and on the day of blastocyst transfer with 5 days of progesterone supplementation (P4d5+). We also calculated the difference of P4d5+ with P4dhCG. (∆P4). Then we divided the patients into two groups based on progesterone serum levels at P4d5+; <10ng/ml (Group A), ≥10ng/ml (Group B). The Student's t-test was performed for continuous variables; Mann-Whitney's Test and Spearman's Test were used where appropriate for categorical variables. p<0.05 was considered statistically significant.

RESULTS

There were positive correlations between βhCG positive with P4d5+ (p<0.001; Rho 0.770) and ∆P4 (p<0.001; Rho 0.703). The pregnancy rate doubled when the serum progesterone level was ≥10ng/ml on the fifth day of progesterone supplementation compared with P4<10ng/ml (44% vs. 21%, respectively).

CONCLUSIONS

The pregnancy rate was positively correlated with the serum P4 level on the fifth day of progesterone supplementation and with the difference between the serum progesterone level in the Dd5+ / dhCG. A higher pregnancy rate was observed when serum progesterone level on the fifth day of progesterone supplementation was ≥10ng/ml.

Supplementary dydrogesterone is beneficial as luteal phase support in artificial frozen-thawed embryo transfer cycles compared to micronized progesterone alone

Introduction

The number of frozen embryo transfers increased substantially in recent years. To increase the chances of implantation, endometrial receptivity and embryo competency must be synchronized. Maturation of the endometrium is facilitated by sequential administration of estrogens, followed by administration of progesterone prior to embryo transfer. The use of progesterone is crucial for pregnancy outcomes. This study compares the reproductive outcomes and tolerability of five different regimens of hormonal luteal phase support in artificial frozen embryo transfer cycles, with the objective of determining the best progesterone luteal phase support in this context.

Design

This is a single-center retrospective cohort study of all women undergoing frozen embryo transfers between 2013 and 2019. After sufficient endometrial thickness was achieved by estradiol, luteal phase support was initiated. The following five different progesterone applications were compared: 1) oral dydrogesterone (30 mg/day), 2) vaginal micronized progesterone gel (90 mg/day), 3) dydrogesterone (20 mg/day) plus micronized progesterone gel (90 mg/day) (dydrogesterone + micronized progesterone gel), 4) micronized progesterone capsules (600 mg/day), and (5) subcutaneous injection of progesterone 25 mg/day (subcutan-P4). The vaginal micronized progesterone gel application served as the reference group. Ultrasound was performed after 12-15 days of oral estrogen (≥4 mg/day) administration. If the endometrial thickness was ≥7 mm, luteal phase support was started, up to six days before frozen embryo transfer, depending on the development of the frozen embryo. The primary outcome was the clinical pregnancy rate. Secondary outcomes included live birth rate, ongoing pregnancy, and miscarriage and biochemical pregnancy rate.

Results

In total, 391 cycles were included in the study (median age of study participants 35 years; IQR 32-38 years, range 26-46 years). The proportions of blastocysts and single transferred embryos were lower in the micronized progesterone gel group. Differences among the five groups in other baseline characteristics were not significant. Multiple logistic regression analysis, adjusting for pre-defined covariates, showed that the clinical pregnancy rates were higher in the oral dydrogesterone only group (OR = 2.87, 95% CI 1.38-6.00, p=0.005) and in the dydrogesterone + micronized progesterone gel group (OR = 5.19, 95% CI 1.76-15.36, p = 0.003) compared to micronized progesterone gel alone. The live birth rate was higher in the oral dydrogesterone-only group (OR = 2.58; 95% CI 1.11-6.00; p=0.028) and showed no difference in the smaller dydrogesterone + micronized progesterone gel group (OR = 2.49; 95% CI 0.74-8.38; p=0.14) compared with the reference group.

Conclusion

The application of dydrogesterone in addition to micronized progesterone gel was associated with higher clinical pregnancy rate and live birth rate and then the use of micronized progesterone gel alone. DYD should be evaluated as a promising LPS option in FET Cycles.

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

IMPORTANCE

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION AND SYNTHESIS

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

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

STUDY REGISTRATION

CRD42022357125 (PROSPERO).

The addition of dydrogesterone improves the outcomes of pregnant women with low progesterone levels when receiving vaginal progesterone alone as luteal support in HRT-FET cycles

Purpose

Vaginal progesterone (VP) alone has been used as luteal support (LS) in HRT-FET cycles without measuring serum progesterone concentrations (SPC) because it can achieve adequate intrauterine progesterone levels. However, several reports showed that the co-administration of progestin produced better outcomes than VP alone. We tried to address this discrepancy, focusing on SPC.

Methods

VP was given to 180 women undergoing HRT-FET. We measured SPC when pregnancy was diagnosed on day 14 of LS. We compared assisted reproductive technology outcomes between VP alone versus VP + dydrogesterone (D).

Results

When using VP alone, average SPC in the miscarriage cases (9.6 ng/mL) were significantly lower compared with the ongoing pregnancy (OP) cases (14.7 ng/mL). The cut-off value for progesterone, 10.7 ng/mL, was a good predictor for the subsequent course of the pregnancy. Of 76 women receiving D ± VP from the start of LS and achieving a pregnancy, the numbers of OP were 44 (84.6%) in SPC ≥ 10.7 ng/mL and 20 (83.3%) in SPC ≤ 10.7 ng/mL with no significant difference.

Conclusion

VP alone resulted in lower SPC in some pregnant women in HRT-FET cycles and exhibited a lower OP rate. The co-administration of D improved an OP rate of low progesterone cases to the level comparable with non-low progesterone cases.

Oral, vaginal or intramuscular progesterone in programmed frozen embryo transfer cycles: a pilot randomized controlled trial

RESEARCH QUESTION

What should be the optimal route of luteal support in programmed frozen embryo transfer (FET) cycles?

DESIGN

This was a randomized, parallel, phase IV pilot trial with three groups of women undergoing FET along with hormone replacement therapy for endometrial preparation at a tertiary private IVF centre (NCT03948022). Women with at least one autologous cryopreserved blastocyst were included. After preparing the endometrium with oestradiol, 151 women were randomly assigned to one of the following three progesterone arms before embryo transfer: oral (10 mg) dydrogesterone (DYD), total daily dose 40 mg (n = 52); 8% (90 mg) progesterone vaginal gel (VAG), total daily dose 180 mg (n = 55); or intramuscular progesterone (IMP) 50 mg/ml in oil, total daily dose 100 mg (n = 44). One or two vitrified-warmed blastocysts were transferred after 5 days' progesterone support.

RESULTS

Baseline demographic features and embryological data were comparable among the groups. Ongoing pregnancy rates (40.4%, 38.2% and 45.5% in the DYD, VAG and IMP arms; P = 0.76) and live birth rates (40.4%, 38.2% and 43.2% in the DYD, VAG and IMP arms, P = 0.61) were statistically similar. Biochemical pregnancy rates and clinical miscarriage rates were also statistically similar among the groups. Significantly more patients with at least one side effect and moderate-to-severe side effects were documented in the IMP arm than the other groups (P < 0.001).

CONCLUSIONS

Treatment with 40 mg/day oral DYD, 180 mg/day progesterone VAG gel or 100 mg/day IMP revealed similar reproductive outcomes in programmed FET cycles. Side effects were significantly more frequent in the IMP arm.

The effect of frozen embryo transfer regimen on the association between serum progesterone and live birth: a multicentre prospective cohort study (ProFET)

STUDY QUESTION

What is the association between serum progesterone levels on the day of frozen embryo transfer (FET) and the probability of live birth in women undergoing different FET regimens?

SUMMARY ANSWER

Overall, serum progesterone levels <7.8 ng/ml were associated with reduced odds of live birth, although the association between serum progesterone levels and the probability of live birth appeared to vary according to the route of progesterone administration.

WHAT IS KNOWN ALREADY

Progesterone is essential for pregnancy success. A recent systematic review showed that in FET cycles using vaginal progesterone for endometrial preparation, lower serum progesterone levels (<10 ng/ml) were associated with a reduction in live birth rates and higher chance of miscarriage. However, there was uncertainty about the association between serum progesterone levels and treatment outcomes in natural cycle FET (NC-FET) and HRT-FET using non-vaginal routes of progesterone administration.

STUDY DESIGN SIZE DURATION

This was a multicentre (n = 8) prospective cohort study conducted in the UK between January 2020 and February 2021.

PARTICIPANTS/MATERIALS SETTING METHODS

We included women having NC-FET or HRT-FET treatment with progesterone administration by any available route. Women underwent venepuncture on the day of embryo transfer. Participants and clinical personnel were blinded to the serum progesterone levels. We conducted unadjusted and multivariable logistic regression analyses to investigate the association between serum progesterone levels on the day of FET and treatment outcomes according to the type of cycle and route of exogenous progesterone administration. Our primary outcome was the live birth rate per participant.

MAIN RESULTS AND THE ROLE OF CHANCE

We studied a total of 402 women. The mean (SD) serum progesterone level was 14.9 (7.5) ng/ml. Overall, the mean adjusted probability of live birth increased non-linearly from 37.6% (95% CI 26.3-48.9%) to 45.5% (95% CI 32.1-58.9%) as serum progesterone rose between the 10th (7.8 ng/ml) and 90th (24.0 ng/ml) centiles. In comparison to participants whose serum progesterone level was ≥7.8 ng/ml, those with lower progesterone (<7.8 ng/ml, 10th centile) experienced fewer live births (28.2% versus 40.0%, adjusted odds ratio [aOR] 0.41, 95% CI 0.18-0.91, P = 0.028), lower odds of clinical pregnancy (30.8% versus 45.1%, aOR 0.36, 95% CI 0.16-0.79, P = 0.011) and a trend towards increased odds of miscarriage (42.1% versus 28.7%, aOR 2.58, 95% CI 0.88-7.62, P = 0.086). In women receiving vaginal progesterone, the mean adjusted probability of live birth increased as serum progesterone levels rose, whereas women having exclusively subcutaneous progesterone experienced a reduction in the mean probability of live birth as progesterone levels rose beyond 16.3 ng/ml. The combination of vaginal and subcutaneous routes appeared to exert little impact upon the mean probability of live birth in relation to serum progesterone levels.

LIMITATIONS REASONS FOR CAUTION

The final sample size was smaller than originally planned, although our study was adequately powered to confidently identify a difference in live birth between optimal and inadequate progesterone levels. Furthermore, our cohort did not include women receiving oral or rectal progestogens.

WIDER IMPLICATIONS OF THE FINDINGS

Our results corroborate existing evidence suggesting that lower serum progesterone levels hinder FET success. However, the relationship between serum progesterone and the probability of live birth appears to be non-linear in women receiving exclusively subcutaneous progesterone, suggesting that in this subgroup of women, high serum progesterone may also be detrimental to treatment success.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by CARE Fertility and a doctoral research fellowship (awarded to P.M.) by the Tommy's Charity and the University of Birmingham. M.J.P. is supported by the NIHR Birmingham Biomedical Research Centre. S.F. is a minor shareholder of CARE Fertility but has no financial or other interest with progesterone testing or manufacturing companies. P.L. reports personal fees from Pharmasure, outside the submitted work. G.P. reports personal fees from Besins Healthcare, outside the submitted work. M.W. reports personal fees from Ferring Pharmaceuticals, outside the submitted work. The remaining authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT04170517.

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

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

Endometrial HLA-F expression is influenced by genotypes and correlates differently with immune cell infiltration in IVF and recurrent implantation failure patients

STUDY QUESTION

Is human leukocyte antigen (HLA)-F protein expressed in mid-secretory endometrium, and are its expression levels influenced by HLA-F gene polymorphisms and correlated with the abundance of uterine natural killer (uNK) cells and anti-inflammatory M2 macrophages?

SUMMARY ANSWER

HLA-F protein is expressed in mid-secretory endometrium, and levels are correlated with immune cell infiltration, plasma progesterone concentrations and HLA-F single-nucleotide polymorphisms (SNPs), however, women experiencing recurrent implantation failure (RIF) show differences when compared to women attending their first IVF treatment.

WHAT IS KNOWN ALREADY

The immunomodulatory HLA class Ib molecules HLA-G and HLA-F are expressed on the extravillous trophoblast cells and interact with receptors on maternal immune cells. Little is known regarding HLA-F expression in endometrial stroma and HLA-F function; furthermore, HLA-F and HLA-G SNP genotypes and haplotypes have been correlated with differences in time-to-pregnancy.

STUDY DESIGN, SIZE, DURATION

Primary endometrial stromal cell (ESC) cultures (n = 5) were established from endometrial biopsies from women attending IVF treatment at a fertility clinic. Basic HLA-F and HLA-G protein expression by the ESCs were investigated. A prospective controlled cohort study was performed including 85 women with a history of RIF and 36 control women beginning their first fertility treatment and with no history of RIF. In some analyses, the RIF group was divided into unknown cause, male infertility, female infertility, and both female and male infertility. Endometrial biopsies and blood samples were obtained the day equivalent to embryo transfer in a hormone-substituted cycle.

PARTICIPANTS/MATERIALS, SETTING, METHODS

HLA protein expression by ESCs was characterized using flow cytometry and western blot. In the cohort study, the specific immune markers HLA-F and HLA-G, CD56 and CD16 (NK cells), CD163 (M2 macrophages), FOXP3 (regulatory T cells) and CD138 (plasma cells) were analysed by immunohistochemistry and a digital image analysis system in endometrial biopsies. Endometrial receptivity was assessed by an endometrial receptivity array test (the ERA® test). Endometrial biopsies were examined according to modified Noyes' criteria. SNPs at the HLA-F gene and HLA-G haplotypes were determined.

MAIN RESULTS AND THE ROLE OF CHANCE

HLA-F protein is expressed in the endometrium at the time of implantation. Furthermore, the HLA-F protein levels were different according to the womeńs HLA-F SNP genotypes and diplotypes, which have previously been correlated with differences in time-to-pregnancy. Endometrial HLA-F was positively correlated with anti-inflammatory CD163+ M2 macrophage infiltration and CD56+ uNK cell abundance for the entire cohort. However, this was not the case for CD56+ in the female infertility RIF subgroup. HLA-F levels in the endometrial stroma were negatively correlated with plasma progesterone concentrations in the RIF subgroup with known female infertility. Conversely, HLA-F and progesterone were positively correlated in the RIF subgroup with infertility of the male partner and no infertility diagnosis of the woman indicating interconnections between progesterone, HLA-F and immune cell infiltration. Glandular sHLA-G expression was also positively correlated with uNK cell abundance in the RIF subgroup with no female infertility but negatively correlated in the RIF subgroup with a female infertility diagnosis.

LARGE SCALE DATA

Immunohistochemistry analyses of endometrial biopsies and DNA sequencing of HLA genes. Data will be shared upon reasonable request to the corresponding author.

LIMITATIONS, REASONS FOR CAUTION

The control group of women attending their first IVF treatment had an anticipated good prognosis but was not proven fertile. A significant age difference between the RIF group and the IVF group reflects the longer treatment period for women with a history of RIF. The standardization of hormonal endometrial preparation, which allowed consistent timing of endometrial and blood sampling, might be a strength because a more uniform hormonal background may more clearly show an influence on the immune marker profile and HLA class Ib levels in the endometrium by other factors, for example genetic polymorphisms. However, the immune marker profile might be different during a normal cycle.

WIDER IMPLICATIONS OF THE FINDINGS

The findings further highlight the importance of HLA-F and HLA-G at the implantation site and in early pregnancy for pregnancy success. Diagnostic measures and modulation of the complex interactions between HLA class Ib molecules, maternal immune cells and hormonal factors may have potential to improve fertility treatment.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Region Zealand Health Sciences Research Foundation and the Zealand University Hospital through the ReproHealth Research Consortium ZUH. The authors declared there are no conflicts of interest.

Effervescent Progesterone Vaginal Tablet Mono-Administration Demonstrated Comparable Pregnancy Rate Across the Different Serum Progesterone Levels on the Day of Embryo Transfer in SHIFT Study

Background: Hormone replacement (HR)-frozen thawed embryo transfer (FET) is preferentially used in Japan. HR-FET needs supplementation of progesterone, but there are few data about the efficacy and safety of vaginal progesterone tablet. The aim of this study is to investigate the efficacy of vaginal progesterone tablet in HR-FET cycle in Japanese patients.

Methods: This study was multicenter, single arm, prospective study. Patients with infertility were administered 300 mg/day of vaginal progesterone tablet for luteal phase support in HR-FET cycle from 2015 to 2016.

Results: Main outcomes were available for 344 patients, of which 49 in the cleavage stage ET group and 295 in the blastocyst ET group. Ongoing pregnancy rate were 10.2% in cleavage stage ET group and 28.1% in blastocyst ET group. As for the secondary outcomes in the blastocyst ET group, embryo quality of blastocyst, the number of past ET, and maternal age were significantly associated with pregnancy rate at 2 weeks after progesterone administration. Mean serum progesterone level was 12.1 ± 5.3 ng/mL at the day of ET. There was no relationship between the serum progesterone level on ET day and either of pregnancy rates at 2, 4, and 6 weeks after progesterone administration.

Conclusions: The efficacy of monotherapy using 300 mg/day of vaginal progesterone tablet in HR-FET was shown and the serum progesterone level on ET day did not affect pregnancy rate. (UMIN000021983)

Comparison of two endometrial preparation methods for frozen-thawed embryo transfer in anovulatory PCOS patients: impact on miscarriage rate

OBJECTIVE

- Some studies have suggested that patients with polycystic ovary syndrome (PCOS) are at high risk of miscarriage. However, this still remains controversial. Several potential factors might explain this association: obesity, hyperinsulinemia and hyperandrogenism. Artificial and stimulated cycles appear to be comparable for endometrial preparation in frozen-thawed embryo transfer (FET) in PCOS patients. Only a few studies have assessed miscarriage rates specifically in PCOS. We have evaluated the impact of endometrial preparation on FET outcomes in anovulatory PCOS patients.

METHODS

- A retrospective cohort study was conducted at the Lille University Hospital, including 255 FET cycles in 134 PCOS patients between January 2011 and December 2017. PCOS was defined by the presence of at least two of the three Rotterdam's criteria. Patients were under 35 years old. Two endometrial preparation protocol were studied: stimulated cycle (gonadotropins on the second day of the cycle and luteal phase support including natural progesterone 600 mg/day) and artificial cycle (6 mg oral estradiol valerate and 800 mg micronized vaginal progesterone daily).

RESULTS

- 137 FET were performed under stimulated cycle and 118 FET under artificial cycle. Early pregnancy rates (30% versus 37.3%, p = NS), miscarriage rates (22% versus 25%, p = NS) and live birth rates (23.4% versus 26.3%, p = NS) were similar.

CONCLUSIONS

- In anovulatory PCOS women, the type of endometrial preparation does not influence FET outcomes, specifically regarding the miscarriage rate.

Retrospective review of reproductive outcomes comparing vaginal progesterone to intramuscular progesterone as luteal support in frozen embryo transfer cycles

OBJECTIVE

Recent literature suggests that progesterone in oil (PIO) is superior to vaginal progesterone (VP; Prometrium) for endometrial preparation in frozen embryo transfer cycles (FET), improving the live birth rate and reducing the rate of miscarriage. PIO has disadvantages including cost, pain, and stress of administration.

METHODS

We conducted a retrospective analysis comparing pregnancy, miscarriage, and live birth rates for PIO versus VP for medicated FET cycles, from 2017 to 2020 at a single fertility clinic. A total of 745 participants were included in the study; 438 received VP, and 307 received PIO. Univariate and multivariate binary and ordinal logistic regression analyses were performed to compare the rates of pregnancy, miscarriage, and live birth between VP and PIO.

RESULTS

Our data demonstrated no difference between PIO and VP with respect to the rates of pregnancy (51% vs. 53%), miscarriage (20% vs. 18%), or live birth (31% vs. 34%) (all P > 0.05).

CONCLUSION

In our single-centre experience, VP was non-inferior to PIO for endometrial preparation in FET cycles.

Natural cycles achieve better pregnancy outcomes than artificial cycles in non-PCOS women undergoing vitrified single-blastocyst transfer: a retrospective cohort study of 6840 cycles

PURPOSE

To identify the optimal method for endometrial preparation in vitrified single-blastocyst transfer (VSBT) cycles.

METHODS

This was a retrospective cohort study for non-PCOS patients who underwent VSBT cycles from March 2015 to November 2019 in an academic reproductive medical center. A total of 6840 VSBT cycles were enrolled and classified into two groups according to different endometrial preparation methods.

RESULTS

The non-PCOS patients who underwent VSBT showed a significantly higher clinical pregnancy rate (61.96% vs 56.85%, p < 0.001) and live birth rate (49.09% vs 39.86%, p < 0.001), as well as a statistically lower early miscarriage rate (12.02% vs 18.08%, p < 0.001) in the natural cycle (NC) group compared with the artificial cycle (AC) group. Multivariable analysis further confirmed that NC was associated with an increased likelihood of clinical pregnancy (adjusted odds ratio (aOR) 0.852, 95% confidence interval (CI) 0.765-0.949, p = 0.004) and live birth (aOR 0.746, 95% CI 0.669-0.832, p < 0 .001), but decreased early miscarriage occurrence (aOR 1.447, 95% CI 1.215-1.724, p < 0.001) compared to AC.

CONCLUSIONS

Our study demonstrated that non-PCOS patients could benefit from NC in vitrified blastocyst transfer. Increased clinical pregnancy rate and decreased early miscarriage rate led to a significantly higher live birth rate in NC patients compared with AC with our present protocol.

Impact of endometrial preparation on early pregnancy loss and live birth rate after frozen embryo transfer: a large multicenter cohort study (14,421 frozen cycles)

STUDY QUESTION

Does the endometrial preparation protocol (artificial cycle (AC) vs natural cycle (NC) vs stimulated cycle (SC)) impact the risk of early pregnancy loss and live birth rate after frozen/thawed embryo transfer (FET)?

SUMMARY ANSWER

In FET, ACs were significantly associated with a higher pregnancy loss rate and a lower live birth rate compared with SC or NC.

WHAT IS KNOWN ALREADY

To date, there is no consensus on the optimal endometrial preparation in terms of outcomes. Although some studies have reported a higher pregnancy loss rate using AC compared with NC or SC, no significant difference was found concerning the pregnancy rate or live birth rate. Furthermore, no study has compared the three protocols in a large population.

STUDY DESIGN, SIZE, DURATION

A multicenter retrospective cohort study was conducted in nine reproductive health units in France using the same software to record medical files between 1 January 2012 and 31 December 2016. FET using endometrial preparation by AC, modified NC or SC were included. The primary outcome was the pregnancy loss rate at 10 weeks of gestation. The sample size required was calculated to detect an increase of 5% in the pregnancy loss rate (21–26%), with an alpha risk of 0.5 and a power of 0.8. We calculated that 1126 pregnancies were needed in each group, i.e. 3378 in total.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were collected by automatic extraction using the same protocol. All consecutive autologous FET cycles were included: 14 421 cycles (AC: n = 8139; NC: n = 3126; SC: n = 3156) corresponding to 3844 pregnancies (hCG > 100 IU/l) (AC: n = 2214; NC: n = 812; SC: n = 818). Each center completed an online questionnaire describing its routine practice for FET, particularly the reason for choosing one protocol over another.

MAIN RESULTS AND THE ROLE OF CHANCE

AC represented 56.5% of FET cycles. Mean age of women was 33.5 (SD ± 4.3) years. The mean number of embryos transferred was 1.5 (±0.5). Groups were comparable, except for history of ovulation disorders (P = 0.01) and prior delivery (P = 0.03), which were significantly higher with AC. Overall, the early pregnancy loss rate was 31.5% (AC: 36.5%; NC: 25.6%; SC: 23.6%). Univariable analysis showed a significant association between early pregnancy loss rate and age >38 years, history of early pregnancy loss, ovulation disorders and duration of cryopreservation >6 months. After adjustment (multivariable regression), the early pregnancy loss rate remained significantly higher in AC vs NC (odds ratio (OR) 1.63 (95% CI) [1.35–1.97]; P < 0.0001) and in AC vs SC (OR 1.87 [1.55–2.26]; P < 0.0001). The biochemical pregnancy rate (hCG > 10 and lower than 100 IU/l) was comparable between the three protocols: 10.7% per transfer.

LIMITATIONS, REASONS FOR CAUTION

This study is limited by its retrospective design that generates missing data. Routine practice within centers was heterogeneous. However, luteal phase support and timing of embryo transfer were similar in AC. Univariable analysis showed no difference between centers. Moreover, a large number of parameters were included in the analysis.

WIDER IMPLICATIONS OF THE FINDINGS

Our study shows a significant increase in early pregnancy loss when using AC for endometrial preparation before FET. These results suggest either a larger use of NC or SC, or an improvement of AC by individualizing hormone replacement therapy for patients in order to avoid an excess of pregnancy losses.

STUDY FUNDING/COMPETING INTEREST(S)

The authors declare no conflicts of interest in relation to this work. G.P.-B. declares consulting fees from Ferring, Gedeon-Richter, Merck KGaA, Theramex, Teva; Speaker’s fees or equivalent from Merck KGaA, Ferring, Gedeon-Richter, Theramex, Teva. N.C. declares consulting fees from Ferring, Merck KGaA, Theramex, Teva; Speaker’s fees or equivalent from Merck KGaA, Ferring. C.R. declares a research grant from Ferring, Gedeon-Richter; consulting fees from Gedeon-Richter, Merck KGaA; Speaker’s fees or equivalent from Merck KGaA, Ferring, Gedeon-Richter; E.M.d’A. declares Speaker’s fees or equivalent from Merck KGaA, MSD, Ferring, Gedeon-Richter, Theramex, Teva. I.C-D. declares Speaker’s fees or equivalent from Merck KGaA, MSD, Ferring, Gedeon-Richter, IBSA. N.M. declares a research grant from Merck KGaA, MSD, IBSA; consulting fees from MSD, Ferring, Gedeon-Richter, Merck KGaA; Speaker’s fees or equivalent from Merck KGaA, MSD, Ferring, Gedeon-Richter, Teva, Goodlife, General Electrics.

TRIAL REGISTRATION NUMBER

N/A.

Individualized luteal phase support based on serum progesterone levels in frozen-thawed embryo transfer cycles maximizes reproductive outcomes in a cohort undergoing preimplantation genetic testing

INTRODUCTION

Low serum progesterone concentration on frozen embryo transfer (FET) day in hormone replacement therapy (HRT) cycles results in lower reproductive outcomes. Recent studies showed the efficiency of a "rescue protocol'' to restore reproductive outcomes in these patients. Here, we compared reproductive outcomes in HRT FET cycles in women with low serum progesterone levels who received individualized luteal phase support (iLPS) and in women with adequate serum progesterone levels who underwent in vitro fertilization for pre-implantation genetic testing for structural rearrangements or monogenic disorders.

DESIGN

This retrospective cohort study included women (18-43 years of age) undergoing HRT FET cycles with pre-implantation genetic testing at Montpellier University Hospital between June 2020 and May 2022. A standard HRT was used: vaginal micronized estradiol (6mg/day) followed by vaginal micronized progesterone (VMP; 800 mg/day). Serum progesterone was measured after four doses of VMP: if <11ng/ml, 25mg/day subcutaneous progesterone or 30mg/day oral dydrogesterone was introduced.

RESULTS

125 HRT FET cycles were performed in 111 patients. Oral/subcutaneous progesterone supplementation concerned 39 cycles (n=20 with subcutaneous progesterone and n=19 with oral dydrogesterone). Clinical and laboratory parameters of the cycles were comparable between groups. The ongoing pregnancy rate (OPR) was 41.03% in the supplemented group and 18.60% in the non-supplemented group (p= 0.008). The biochemical pregnancy rate and miscarriages rate tended to be higher in the non-supplemented group versus the supplemented group: 13.95% versus 5.13% and 38.46% versus 15.79% (p=0.147 and 0.182 respectively). Multivariate logistic regression analysis found that progesterone supplementation was significantly associated with higher OPR ​​ (adjusted OR = 3.25, 95% CI [1.38 - 7.68], p=0.007).

CONCLUSION

In HRT FET cycles, progesterone supplementation in patients with serum progesterone concentration <11 ng/mL after four doses of VMP significantly increases the OPR.

Implantation Failures and Miscarriages in Frozen Embryo Transfers Timed in Hormone Replacement Cycles (HRT): A Narrative Review

The recent advent of embryo vitrification and its remarkable efficacy has focused interest on the quality of hormone administration for priming frozen embryo transfers (FETs). Products available for progesterone administration have only been tested in fresh assisted reproduction technologies (ARTs) and not in FET. Recently, there have been numerous concordant reports pointing at the inefficacy of vaginal preparations at delivering sufficient progesterone levels in a sizable fraction of FET patients. The options available for coping with these shortcomings of vaginal progesterone include (i) rescue options with the addition of injectable subcutaneous (SC) progesterone at the dose of 25 mg/day administered either solely to women whose circulating progesterone is <10 ng/mL or to all in a combo option and (ii) the exclusive administration of SC progesterone at the dose of 25 mg BID. The wider use of segmented ART accompanied with FET forces hormone replacement regimens used for priming endometrial receptivity to be adjusted in order to optimize ART outcomes.

Natural vs. programmed cycles for frozen embryo transfer: study protocol for an investigator-initiated, randomized, controlled, multicenter clinical trial

Background

Randomized trials of assisted reproductive technology (ART) have been designed for outcomes of clinical pregnancy or live birth and have not been powered for obstetric outcomes such as preeclampsia, critical for maternal and fetal health. ART increasingly involves frozen embryo transfer (FET). Although there are advantages of FET, multiple studies have shown that risk of preeclampsia is increased with FET compared with fresh embryo transfer, and the reason for this difference is not clear. NatPro will compare the proportion of preeclampsia between two commonly used protocols for FET,modified natural and programmed cycle.

Methods

In this two-arm, parallel-group, multi-center randomized trial, NatPro will randomize 788 women to either modified natural or programmed FET and follow them for up to three FET cycles. Primary outcome will be the proportion of preeclampsia in women with a viable pregnancy assigned to a modified natural cycle FET (corpus luteum present) protocol compared to the proportion of preeclampsia in pregnant women assigned to a programmed FET (corpus luteum absent) protocol. Secondary outcomes will compare the proportion of live births and the proportion of preeclampsia with severe features between the protocols.

Conclusion

This study has a potential significant impact on millions of women who pursue ART to build their families. NatPro is designed to provide clinically relevant guidance to inform patients and clinicians regarding maternal risk with programmed and modified natural cycle FET protocols. This study will also provide accurate point estimates regarding the likelihood of live birth with programmed and modified natural cycle FET.

Trial registration

ClinicalTrials.govNCT04551807. Registered on September 16, 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05637-3.

Beyond the uterine first pass: optimizing programmed frozen embryo transfers. A mini-review

With the greatly increased popularity of segmented in vitro fertilization and frozen embryo transfers, progesterone replacement strategies in programmed cycles are being reexamined. Bidirectionality and the limited capacity of the uterine first pass provide an explanation for disconnects between the endometrial and serum levels when either vaginal or intramuscular progesterone is used alone. Whereas monotherapy departs from the physiology of spontaneous pregnancies, combined therapy provides physiologic replacement while minimizing the number of injections.

Serum luteal phase progesterone in women undergoing frozen embryo transfer in assisted conception: a systematic review and meta-analysis

OBJECTIVE

To investigate the association between luteal serum progesterone levels and frozen embryo transfer (FET) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Women undergoing FET.

INTERVENTION(S)

We conducted electronic searches of MEDLINE, PubMed, CINAHL, EMBASE, the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and grey literature (not widely available) from inception to March 2021 to identify cohort studies in which the serum luteal progesterone level was measured around the time of FET.

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy or live birth rate, clinical pregnancy rate, and miscarriage rate.

RESULT(S)

Among the studies analyzing serum progesterone level thresholds <10 ng/mL, a higher serum progesterone level was associated with increased rates of ongoing pregnancy or live birth (relative risk [RR] 1.47, 95% confidence interval [CI] 1.28 to 1.70), higher chance of clinical pregnancy (RR 1.31, 95% CI 1.16 to 1.49), and lower risk of miscarriage (RR 0.62, 95% CI 0.50 to 0.77) in cycles using exclusively vaginal progesterone and blastocyst embryos. There was uncertainty about whether progesterone thresholds ≥10 ng/mL were associated with FET outcomes in sensitivity analyses including all studies, owing to high interstudy heterogeneity and wide CIs.

CONCLUSION(S)

Our findings indicate that there may be a minimum clinically important luteal serum concentration of progesterone required to ensure an optimal endocrine milieu during embryo implantation and early pregnancy after FET treatment. Future clinical trials are required to assess whether administering higher-dose luteal phase support improves outcomes in women with a low serum progesterone level at the time of FET.

PROSPERO NUMBER

CRD42019157071.

Preparation of the Endometrium for Frozen Embryo Transfer: A Systematic Review

Despite the worldwide increase in frozen embryo transfer, the search for the best protocol to prime endometrium continues. Well-designed trials comparing various frozen embryo transfer protocols in terms of live birth rates, maternal, obstetric and neonatal outcome are urgently required. Currently, low-quality evidence indicates that, natural cycle, either true natural cycle or modified natural cycle, is superior to hormone replacement treatment protocol. Regarding warmed blastocyst transfer and frozen embryo transfer timing, the evidence suggests the 6th day of progesterone start, LH surge+6 day and hCG+7 day in hormone replacement treatment, true natural cycle and modified natural cycle protocols, respectively. Time corrections, due to inter-personal differences in the window of implantation or day of vitrification (day 5 or 6), should be explored further. Recently available evidence clearly indicates that, in hormone replacement treatment and natural cycles, there might be marked inter-personal variation in serum progesterone levels with an impact on reproductive outcomes, despite the use of the same dose and route of progesterone administration. The place of progesterone rescue protocols in patients with low serum progesterone levels one day prior to warmed blastocyst transfer in hormone replacement treatment and natural cycles is likely to be intensively explored in near future.

Length of estradiol exposure >100 pg/ml in the follicular phase affects pregnancy outcomes in natural frozen embryo transfer cycles

STUDY QUESTION

Do the length of follicular phase estradiol exposure and the total length of the follicular phase affect pregnancy and live birth outcomes in natural frozen embryo transfer (FET) cycles?

SUMMARY ANSWER

An estradiol level >100 pg/ml for ≤4 days including the LH surge day is associated with worse pregnancy and live birth outcomes; however, the total length of the follicular phase is not associated with pregnancy and live birth outcomes.

WHAT IS KNOWN ALREADY

An estradiol level that increases above 100 pg/ml and continues to increase is indicative of the selection and development of a dominant follicle. In programmed FET cycles, a limited duration of follicular phase estradiol of <9 days results in worse pregnancy rates, but a prolonged exposure to follicular phase estradiol for up to 4 weeks does not affect pregnancy outcomes. It is unknown how follicular phase characteristics affect pregnancy outcomes in natural FET cycles.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study included infertile patients in an academic hospital setting who underwent their first natural frozen autologous Day-5 embryo transfer cycle in our IVF clinic between 01 January 2013 and 31 December 2018. Donor oocyte and gestational carrier cycles were excluded.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The primary outcomes of this study were pregnancy and live birth rates. Patients were stratified into two groups based on the cohorts' median number of days from the estradiol level of >100 pg/ml before the LH surge: Group 1 (≤4 days; n = 1052 patients) and Group 2 (>4 days; n = 839 patients). Additionally, patients were stratified into two groups based on the cohorts' median cycle day of LH surge: Group 1 (follicular length ≤15 days; n = 1287 patients) and Group 2 (follicular length >15 days; n = 1071 patients). A subgroup analysis of preimplantation genetic testing for aneuploidies (PGT-A) embryo transfer cycles was performed. Logistic regression analysis, adjusted a priori for patient age, number of embryos transferred, and use of PGT-A, was used to estimate the odds ratio (OR) with a 95% CI.

MAIN RESULTS AND THE ROLE OF CHANCE

In the length of elevated estradiol analysis, the pregnancy rate per embryo transfer was statistically significantly lower in patients with an elevated estradiol to surge of ≤4 days (65.6%) compared to patients with an elevated estradiol to surge of >4 days (70.9%; OR 1.30 (95% CI 1.06-1.58)). The live birth rate per embryo transfer was also statistically significantly lower in patients with an elevated estradiol to surge of ≤4 days (46.6%) compared to patients with an elevated estradiol to surge of >4 days (52.0%; OR 1.23 (95% CI 1.02-1.48)). In the follicular phase length analysis, the pregnancy rate per embryo transfer was similar between patients with a follicular length of ≤15 days (65.4%) and patients with a follicular length of >15 days (69.0%; OR 1.12 (95% CI 0.94-1.33)): the live birth rate was also similar between groups (45.5% vs 51.5%, respectively; OR 1.14 (95% CI 0.97-1.35)). In all analyses, once a pregnancy was achieved, the length of the follicular phase or the length of elevated oestradiol >100 pg/ml no longer affected the pregnancy outcomes.

LIMITATIONS, REASONS FOR CAUTION

The retrospective design of this study is subject to possible selection bias in regard to which patients at our clinic were recommended to undergo a natural FET compared to a fresh embryo transfer or programmed FET. To decrease the heterogeneity of our study population, we only included patients who had blastocyst embryo transfers; therefore, it is unknown whether similar results would be observed in patients with cleavage-stage embryo transfers. The retrospective nature of the study design did not allow randomized to a specific ovarian stimulation or ovulation trigger protocol. However, all patients were managed with the standardized protocols at a single center, which strengthens the external validity of our results when compared to a study that only evaluates one specific stimulation protocol.

WIDER IMPLICATIONS OF THE FINDINGS

Our observations provide cycle-level characteristics that can be applied during a natural FET cycle to help optimize embryo transfer success rates. Physicians should consider the parameter of number of days that oestradiol is >100 pg/ml prior to the LH surge when determining whether to proceed with embryo transfer in a natural cycle. This cycle-specific characteristic may also help to provide an explanation for some failed transfer cycles. Importantly, our findings should not be used to determine whether to recommend a natural or a programmed FET cycle for a patient, but rather, to identify natural FET cycles that are not optimal to proceed with embryo transfer.

STUDY FUNDING/COMPETING INTEREST(S)

No financial support, funding, or services were obtained for this study. The authors do not report any potential conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Micronized progesterone plus dydrogesterone versus micronized progesterone alone for luteal phase support in frozen-thawed cycles (MIDRONE): a prospective cohort study

STUDY QUESTION

Does the addition of oral dydrogesterone to vaginal progesterone as luteal phase support improve pregnancy outcomes during frozen embryo transfer (FET) cycles compared with vaginal progesterone alone?

SUMMARY ANSWER

Luteal phase support with oral dydrogesterone added to vaginal progesterone had a higher live birth rate and lower miscarriage rate compared with vaginal progesterone alone.

WHAT IS KNOWN ALREADY

Progesterone is an important hormone that triggers secretory transformation of the endometrium to allow implantation of the embryo. During IVF, exogenous progesterone is administered for luteal phase support. However, there is wide inter-individual variation in absorption of progesterone via the vaginal wall. Oral dydrogesterone is effective and well tolerated when used to provide luteal phase support after fresh embryo transfer. However, there are currently no data on the effectiveness of luteal phase support with the combination of dydrogesterone with vaginal micronized progesterone compared with vaginal micronized progesterone after FET.

STUDY DESIGN, SIZE, DURATION

Prospective cohort study conducted at an academic infertility center in Vietnam from 26 June 2019 to 30 March 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We studied 1364 women undergoing IVF with FET. Luteal support was started when endometrial thickness reached ≥8 mm. The luteal support regimen was either vaginal micronized progesterone 400 mg twice daily plus oral dydrogesterone 10 mg twice daily (second part of the study) or vaginal micronized progesterone 400 mg twice daily (first 4 months of the study). In women with a positive pregnancy test, the appropriate luteal phase support regimen was continued until 7 weeks' gestation. The primary endpoint was live birth after the first FET of the started cycle, with miscarriage <12 weeks as one of the secondary endpoints.

MAIN RESULTS AND THE ROLE OF CHANCE

The vaginal progesterone + dydrogesterone group and vaginal progesterone groups included 732 and 632 participants, respectively. Live birth rates were 46.3% versus 41.3%, respectively (rate ratio [RR] 1.12, 95% CI 0.99-1.27, P = 0.06; multivariate analysis RR 1.30 (95% CI 1.01-1.68), P = 0.042), with a statistically significant lower rate of miscarriage at <12 weeks in the progesterone + dydrogesterone versus progesterone group (3.4% versus 6.6%; RR 0.51, 95% CI 0.32-0.83; P = 0.009). Birth weight of both singletons (2971.0 ± 628.4 versus 3118.8 ± 559.2 g; P = 0.004) and twins (2175.5 ± 494.8 versus 2494.2 ± 584.7; P = 0.002) was significantly lower in the progesterone plus dydrogesterone versus progesterone group.

LIMITATIONS, REASONS FOR CAUTION

The main limitations of the study were the open-label design and the non-randomized nature of the sequential administration of study treatments. However, our systematic comparison of the two strategies was able to be performed much more rapidly than a conventional randomized controlled trial. In addition, the single ethnicity population limits external generalizability.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings study suggest a role for oral dydrogesterone in addition to vaginal progesterone as luteal phase support in FET cycles to reduce the miscarriage rate and improve the live birth rate. Carefully planned prospective cohort studies with limited bias could be used as an alternative to randomized controlled clinical trials to inform clinical practice.

STUDY FUNDING/COMPETING INTERESTS

This study received no external funding. LNV has received speaker and conference fees from Merck, grant, speaker and conference fees from Merck Sharpe and Dohme, and speaker, conference and scientific board fees from Ferring; TMH has received speaker fees from Merck, Merck Sharp and Dohme, and Ferring; R.J.N. has received scientific board fees from Ferring and receives grant funding from the National Health and Medical Research Council (NHMRC) of Australia; BWM has acted as a paid consultant to Merck, ObsEva and Guerbet, and is the recipient of grant money from an NHMRC Investigator Grant.

TRIAL REGISTRATION NUMBER

NCT0399876.

Is there a link between plasma progesterone 1-2 days before frozen embryo transfers (FET) and ART outcomes in frozen blastocyst transfers?

OBJECTIVE

To study the efficacy of combined administration of subcutaneous and vaginal progesterone for priming frozen blastocysts transfers, looking at progesterone levels and ART outcome.

DESIGN

Retrospective study.

SETTING PATIENTS

Three hundred and twenty frozen blastocyst transfer cycles conducted in 213 women aged up to 42 years, BMI between 18 and 30 kg/m², with anatomically normal uterus who underwent frozen embryo transfers (FETs) from February 2019 to December 2019 with a combined luteal-phase support (LPS) associating subcutaneous and vaginal progesterone. Patients with recurrent pregnancy loss (RPL) were excluded.

RESULTS

When using combined vaginal and subcutaneous LPS, SPL >10.50 ng/mL in 95% of cases, with a minimum value of 7.02 ng/mL. CPR, OPR, and global miscarriage rates were 38.4%, 30.9%, and 19.5%, respectively. Analyzing results per quartiles, revealed that miscarriage rates were significantly inferior, and IR were higher in the upper two quartiles of serum progesterone (>21.95 ng/mL) on the day before FET, while there was no difference in CPR and OPR.

CONCLUSIONS

We report ART outcome of frozen blastocyst transfers performed using a combination of vaginal and subcutaneous progesterone for LPS. ART results were honorable and SPL favorable 1-2 days before FET in 99% of cases.

Individualised luteal phase support in artificially prepared frozen embryo transfer cycles based on serum progesterone levels: a prospective cohort study

STUDY QUESTION

Does an individualised luteal phase support (iLPS), according to serum progesterone (P4) level the day prior to euploid frozen embryo transfer (FET), improve pregnancy outcomes when started on the day previous to embryo transfer?

SUMMARY ANSWER

Patients with low serum P4 the day prior to euploid FET can benefit from the addition of daily subcutaneous P4 injections (Psc), when started the day prior to FET, and achieve similar reproductive outcomes compared to those with initial adequate P4 levels.

WHAT IS KNOWN ALREADY

The ratio between FET/IVF has spectacularly increased in the last years mainly thanks to the pursuit of an ovarian hyperstimulation syndrome free clinic and the development of preimplantation genetic testing (PGT). There is currently a big concern regarding the endometrial preparation for FET, especially in relation to serum P4 levels around the time of embryo transfer. Several studies have described impaired pregnancy outcomes in those patients with low P4 levels around the time of FET, considering 10 ng/ml as one of the most accepted reference values. To date, no prospective study has been designed to compare the reproductive outcomes between patients with adequate P4 the day previous to euploid FET and those with low, but restored P4 levels on the transfer day after iLPS through daily Psc started on the day previous to FET.

STUDY DESIGN, SIZE, DURATION

A prospective observational study was conducted at a university-affiliated fertility centre between November 2018 and January 2020 in patients undergoing PGT for aneuploidies (PGT-A) IVF cycles and a subsequent FET under hormone replacement treatment (HRT). A total of 574 cycles (453 patients) were analysed: 348 cycles (leading to 342 euploid FET) with adequate P4 on the day previous to FET, and 226 cycles (leading to 220 euploid FET) under iLPS after low P4 on the previous day to FET, but restored P4 levels on the transfer day.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall we included 574 HRT FET cycles (453 patients). Standard HRT was used for endometrial preparation. P4 levels were measured the day previous to euploid FET. P4 > 10.6 ng/ml was considered as adequate and euploid FET was performed on the following day (FET Group 1). P4 < 10.6 ng/ml was considered as low, iLPS was added in the form of daily Psc injections, and a new P4 analysis was performed on the following day. FET was only performed on the same day when a restored P4 > 10.6 ng/ml was achieved (98.2% of cases) (FET Group 2).

MAIN RESULTS AND THE ROLE OF CHANCE

Patient's demographics and cycle parameters were comparable between both euploid FET groups (FET Group 1 and FET Group 2) in terms of age, weight, oestradiol and P4 levels and number of embryos transferred. No statistically significant differences were found in terms of clinical pregnancy rate (56.4% vs 59.1%: rate difference (RD) -2.7%, 95% CI [-11.4; 6.0]), ongoing pregnancy rate (49.4% vs 53.6%: RD -4.2%, 95% CI [-13.1; 4.7]) or live birth rate (49.1% vs 52.3%: RD -3.2%, 95% CI [-12; 5.7]). No significant differences were also found according to miscarriage rate (12.4% vs 9.2%: RD 3.2%, 95% CI [-4.3; 10.7]).

LIMITATIONS, REASONS FOR CAUTION

Only iLPS through daily Psc was evaluated. The time for Psc injection was not stated and no serum P4 determinations were performed once the pregnancy was achieved.

WIDER IMPLICATIONS OF THE FINDINGS

Our study provides information regarding an 'opportunity window' for improved ongoing pregnancy rates and miscarriage rates through a daily Psc injection in cases of inadequate P4 levels the day previous to FET (P4 < 10.6 ng/ml) and restored values the day of FET (P4 > 10.6 ng/ml). Only euploid FET under HRT were considered, avoiding one of the main reasons of miscarriage and implantation failure and overcoming confounding factors such as female age, embryo quality or ovarian stimulation protocols.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received. B.C. reports personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, IBSA and Gedeon Richter outside the submitted work. N.P. reports grants and personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, Theramex and Besins International and personal fees from IBSA and Gedeon Richter outside the submitted work. The remaining authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NCT03740568.

When Should We Freeze Embryos? Current Data for Fresh and Frozen Embryo Replacement IVF Cycles

Recent years have seen a dramatic rise in the number of frozen-thawed embryo replacement (FER) cycles. Along with the advances in embryo cryopreservation techniques, the optimization of endometrial receptivity has resulted in outcomes for FER that are similar to fresh embryo transfer. However, the question of whether the Freeze all strategy is for all is nowadays a hot topic. This review addresses this issue and describes current evidence based on randomized controlled trials and observational studies. To date, it is reasonable to perform FER in cases with a clear indication for the benefits of such strategy including impending ovarian hyperstimulation syndrome (OHSS) or preimplantation genetic testing for aneuploidy (PGT-A); however, this strategy does not fit for all. This review analyses the pros and cons of the freeze all strategy highlighting the need to follow a personalized plan in embryo transfer, avoiding a freeze all methodology for all patients in an unselected manner.

Intramuscular progesterone optimizes live birth from programmed frozen embryo transfer: a randomized clinical trial

OBJECTIVE

To determine whether vaginal progesterone for programmed endometrial preparation is noninferior to intramuscular progesterone in terms of live birth rates from frozen embryo transfer (FET).

DESIGN

Three-armed, randomized, controlled noninferiority trial.

SETTING

Multicenter fertility clinic.

PATIENT(S)

A total of 1,346 volunteer subjects planning vitrified-warmed transfer of high-quality nonbiopsied blastocysts were screened, of whom 1,125 subjects were ultimately enrolled and randomly assigned to treatment.

INTERVENTION(S)

The subjects were randomly assigned to receive, in preparation for FET, 50 mg daily of intramuscular progesterone (control group), 200 mg twice daily of vaginal micronized progesterone plus 50 mg of intramuscular progesterone every third day (combination treatment), or 200 mg twice daily of vaginal micronized progesterone.

MAIN OUTCOME MEASURE(S)

The primary outcome was live birth rate per vitrified-warmed embryo transfer. The secondary outcomes were a positive serum human chorionic gonadotropin test 2 weeks after FET, biochemical pregnancy loss, clinical pregnancy, clinical pregnancy loss, total pregnancy loss, serum luteal progesterone concentration 2 weeks after FET, and patient's experience and attitudes regarding the route of progesterone administration, on the basis of a survey administered to the subjects between FET and pregnancy test.

RESULT(S)

A total of 1,060 FETs were completed. The live birth rate was significantly lower in women receiving only vaginal progesterone (27%) than in women receiving intramuscular progesterone (44%) or combination treatment (46%). Fifty percent of pregnancies in women receiving only vaginal progesterone ended in miscarriage.

CONCLUSION(S)

The live birth rate after vaginal-only progesterone replacement was significantly reduced, due primarily to an increased rate of miscarriage. Vaginal progesterone supplemented with intramuscular progesterone every third day was noninferior to daily intramuscular progesterone, offering an effective alternative regimen with fewer injections.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02254577.

Strengthened luteal phase support for patients with low serum progesterone on the day of frozen embryo transfer in artificial endometrial preparation cycles: a large-sample retrospective trial

BACKGROUND

Low serum progesterone on the day of frozen embryo transfer (FET) is associated with diminished pregnancy rates in artificial endometrium preparation cycles, but there is no consensus on whether strengthened luteal phase support (LPS) benefits patients with low progesterone on the FET day in artificial cycles. This single-centre, large-sample retrospective trial was designed to investigate the contribution of strengthened LPS to pregnancy outcomes for groups with low progesterone levels on the FET day in artificial endometrium preparation cycles.

METHODS

Women who had undergone the first artificial endometrium preparation cycle after a freeze-all protocol in our clinic from 2016 to 2018 were classified into two groups depending on their serum progesterone levels on the FET day. Routine LPS was administered to group B (P ≥ 10.0 ng/ml on the FET day, n = 1261), and strengthened LPS (routine LPS+ im P 40 mg daily) was administered to group A (P < 10.0 ng/ml on the FET day, n = 1295). The primary endpoint was the live birth rate, and the secondary endpoints were clinical pregnancy, miscarriage and neonatal outcomes.

RESULTS

The results showed that the clinical pregnancy rate was significantly lower in group A than in group B (48.4% vs 53.2%, adjusted risk ratio (aRR) 0.81, 95% confidence interval (CI) 0.68, 0.96), whereas miscarriage rates were similar between the two groups (16.0% vs 14.7%, aRR 1.09, 95% CI 0.77, 1.54). The live birth rate was slightly lower in group A than in group B (39.5% vs 43.3%, aRR 0.84, 95% CI 0.70, 1.0). Birthweights and other neonatal outcomes were similar between the two groups (P > 0.05).

CONCLUSIONS

The results indicated that the serum progesterone level on the FET day was one of the risk factors predicting the chances of pregnancy in artificial endometrium preparation cycles, and strengthened LPS in patients with low progesterone on the FET day might help to provide a reasonable pregnancy outcome in artificial cycles, although further prospective evidence is needed to confirm this possibility.

Comparison of vaginal progesterone gel combined with oral dydrogesterone versus intramuscular progesterone for luteal support in hormone replacement therapy-frozen embryo transfer cycle

BACKGROUND

It remains under subject of debate regarding the optimal route of luteal support for hormone replacement therapy- frozen embryo transfer (HRT-FET) cycles. We compared efficacy of vaginal progesterone gel combined with oral dydrogesterone and intramuscular progesterone for HRT-FET lutein support.

METHODS

This is a retrospective observational study. After matching for propensity score of getting vaginal + oral treatment, a total of 208 FET cycles in the vaginal progesterone combined with oral dydrogesterone and 624 cycles in the intramuscular progesterone group were enrolled. Pregnancy outcomes and neonatal outcomes including chemical pregnancy rate, clinical pregnancy rate, implantation rate, spontaneous abortion rate, live birth rate, gestational weeks, pre-term delivery, birth weight, and congenital anomalies rate were compared.

RESULTS

No significant differences were observed in patient characteristics such as age, duration of infertility, type of infertility, or hormone level after matching. Chemical pregnancy rate (68.3 % versus 70.5 %), clinical pregnancy rate (64.9 % versus 64.4 %), implantation rate (52.3 % versus 50.2 %), spontaneous abortion rate (21.5 % versus 18.4 %), and live birth rate (49.0 % versus 51.3 %) were similar in both group without statistically significant difference. No significant differences in neonatal outcomes were observed between the two groups.

CONCLUSION

We observed similar pregnancy outcomes in both vaginal progesterone gel combined with oral dydrogesterone and intramuscular progesterone protocol. Vaginal progesterone gel combined with oral dydrogesterone can be substituted for intramuscular progesterone given that vaginal plus oral use has good safety and is more convenient and may be associated with less side effect caused by intramuscular injection.

Gestational carrier pregnancy outcomes from frozen embryo transfer depending on the number of embryos transferred and preimplantation genetic testing: a retrospective analysis

OBJECTIVE

To compare gestational age, birth weight (BW), and live birth rates in gestational carriers (GC) after the transfer of 1 or 2 frozen embryo(s) with or without preimplantation genetic testing for aneuploidy (PGT-A), with the understanding that several social and economic factors may motivate intended parents to request the transfer of 2 embryos and/or PGT-A when using a GC.

DESIGN

Retrospective cohort study SETTING: An assisted reproductive technology practice.

PATIENT(S)

All frozen blastocyst transfers with GCs from 2009-2018.

INTERVENTION(S)

One or 2 embryo frozen embryo transfers with and without PGT-A.

MAIN OUTCOME MEASURE(S)

Live birth, preterm birth, and low BW.

RESULTS

A total of 583 frozen embryo transfer cycles with vitrified high-grade blastocysts (grade BB or higher) to GCs were analyzed. Although the live birth rate was significantly greater in frozen embryo transfers with 2 embryos, after single embryo transfer (SET), the mean gestational age and BW of live births were statistically significantly greater than those of double embryo transfer (DET). The rate of multiple births was 1.9% for SET compared to 20.0% for DET per transfer. Only 3.8% of live births from SET experienced low BW and 0.6% had very low or extremely low BW. By comparison, 12.5% of DET live births were low BW and 5% were very low BW. After SET, 13.4% of live births were preterm, compared with 40% in DET. The analysis also included a total of 194 transfers with PGT-A compared to 389 cycles without. Overall, live births per transfer were not significantly different between these latter 2 subgroups.

CONCLUSION

Frozen embryo transfer cycles in GCs with DET were associated with more preterm births and lower birth weights compared with those of SET. Intended parents and GCs should be counseled that DET is associated with greater risks of adverse pregnancy and perinatal outcomes, which mitigates higher live birth rates. The use of PGT-A did not appear to improve the live birth rate.

Routine endometrial receptivity array in first embryo transfer cycles does not improve live birth rate

OBJECTIVE

To compare the live birth rate between patients who undergo personalized embryo transfer (pET) after endometrial receptivity array (ERA) versus frozen embryo transfer (FET) with standard timing in first single euploid FET cycles. To report the rate of displacement of the window of implantation (WOI) in an infertile population without a history of implantation failure.

DESIGN

Prospective cohort study of patients who underwent their first single euploid programmed FET.

SETTING

Private fertility clinic.

PATIENT(S)

Patients who underwent first autologous single euploid programmed FET between January 2018 and April 2019.

INTERVENTION(S)

Endometrial biopsy with ERA followed by pET as indicated.

MAIN OUTCOME MEASURE(S)

Live birth rate and rate of receptive and nonreceptive ERA.

RESULT(S)

A total of 228 single euploid FET cycles were included in our analysis. Of those, 147 (64.5%) were ERA/pET cycles, and 81 (35.5%) were standard timing FET cycles. Endometrial receptivity array was receptive in 60/147 (40.8%) and nonreceptive in 87/147 (59.2%) patients. Nonreceptive ERAs were prereceptive in 93.1% of cases. The live birth rate did not differ between patients who underwent FET with standard timing and patients who underwent ERA/pET, 45/81 (56.6%) and 83/147 (56.5%), respectively.

CONCLUSION(S)

Our data do not support the routine use of ERA in an unselected patient population undergoing first autologous single euploid programmed embryo transfer.

Should the modified natural cycle protocol for frozen embryo transfer be modified? A prospective case series proof of concept study

OBJECTIVE

Modified natural cycles for frozen embryo transfer utilize an ovulation trigger which assists in embryo transfer scheduling and simplifies cycle monitoring. There have been conflicting results with this protocol and modifications may be sought. We wanted to ascertain whether a modified natural protocol for frozen embryo transfer without triggered ovulation but with luteal progesterone support disconnecting the timing of embryo transfer from the timing of the LH surge can achieve a high pregnancy rate.

STUDY DESIGN

Candidates for frozen embryo transfer of 48-h cleavage cell embryos were recruited from May 2016 to April 2018. The patients were monitored for endometrial growth, follicle formation and estradiol, progesterone, and LH hormone levels. After meeting the predetermined criteria, embryo transfer was scheduled. The patients began progesterone treatment 48 h before embryo transfer, regardless of identification of the LH surge if ovulation had not commenced. The predetermined primary outcome was the biochemical pregnancy rate while the secondary outcome included the clinical pregnancy rate and the ongoing pregnancy rate. Patients were monitored to the eighth week of pregnancy, but data was collected from the medical records to provide the live birth rate as well.

RESULTS

Fifty-six women were screened. Eleven women declined or did not meet the inclusion criteria. Three had anovulatory cycles and were excluded. Forty-two women were included in the statistical analysis. The implantation rate was 42.9 % [95 %CI 29.3 %-56.4 %). Of the 42 participants, 25 (59.5 %) conceived [95 % CI 44.0 %-75 %]. Two pregnancies ended in first trimester miscarriage leaving 23 (54.7 %) ongoing pregnancies [95 % CI 39.1 %-70.5 %]. One patient experienced a late abortion such that the live birth rate was 22 of 42 patients or 52.4 % [95 % CI 36.4 %-68.0 %].

CONCLUSION

The proposed modified natural protocol which utilizes progesterone luteal support but does not trigger ovulation, maintains a high pregnancy rate while providing flexibility regarding the day of transfer disconnected from the day of the LH surge. This was a prospective, proof of concept study. This protocol may be suitable for smaller or public in-vitro fertility units whose resources are limited and facilities are not available daily. The high pregnancy and live birth rate that we found provides confidence that this protocol can be part of the armament of protocols the clinician may offer to his patients. Larger studies should confirm these findings.

Women utilizing oocyte donation have a decreased live birth rate if they displayed a low progesterone level in a previous hormonal replacement mock cycle

PURPOSE

Is serum progesterone(P) level on day 2 of vaginal P administration in a hormonally substituted mock cycle predictive of live birth in oocyte donation(OD)?

METHODS

Retrospective analysis of 110 mock cycles from 2008 to 2016 of OD recipients having at least one subsequent embryo transfer (ET). Endometrial preparation consisted of sequential administration of vaginal estradiol, followed by transdermal estradiol and 600 mg/day vaginal micronized P. In mock cycles, serum P was measured 2 days after vaginal P introduction. OD was performed 1 to 3 years later, without P measurement.

RESULTS

In mock cycles, mean serum P level on day 2 was 12.8 ± 4.5 ng/mL (range: 4-28 ng/mL). A total of 32% patients had P < 10 ng/mL. At the time of first OD, age of recipients and donors, number of retrieved and attributed oocytes, and number of transferred embryos were comparable between patients with P < 10 ng/mL in their mock cycles compared with P ≥ 10 ng/mL. Pregnancy and live birth rate after first ET were significantly lower for patients with P < 10ng/mL (9% vs. 35 %; P = 0.002 and 9% vs. 32%; P = 0.008, respectively). Considering both fresh and subsequent frozen-thawed ET, cumulative live birth rate per-patient and per-transfer were significantly lower in patients with P < 10 ng/mL in their mock cycle (14% vs. 35%; P = 0.02 and 11% vs. 27%; P = 0.03).

CONCLUSION

A low P level in hormonally substituted cycles several years before ET performed with the same endometrial preparation is associated with a significantly lower chance of live birth. This suggests that altered vaginal P absorption is a permanent phenomenon. Monitoring serum P in hormonally substituted cycles appears mandatory to adjust luteal P substitution.