Immediate versus delayed single blastocyst transfer following the first stimulated IVF cycle in the freeze-all strategy: a study protocol for a randomised controlled trial

INTRODUCTION

In recent years, the use of frozen embryo transfers (FET) has rapidly increased following the freeze-all strategy due to the advantages of increased maternal safety, improved pregnancy rates, lower ectopic pregnancy rates and better obstetric and neonatal outcomes. Currently, there is still no good scientific evidence to support when to perform FET following a stimulated in vitro fertilisation (IVF) cycle in the freeze-all strategy.

METHODS/ANALYSIS

This will be a randomised controlled trial. A total of 828 women undergoing their first FET following their first stimulated IVF cycle in the freeze-all strategy will be enrolled and randomised into one of the following groups according to a computer-generated randomisation list: (1) the immediate group, in which FET will be performed in the first menstrual cycle following the stimulated IVF cycle; or (2) the delayed group, in which FET will be performed at least in the second menstrual cycle following the stimulated IVF cycle. The primary outcome will be live birth, which is defined as the delivery of any infants at ≥22 gestational weeks with heartbeat and breath.

ETHICS/DISSEMINATION

Ethical approval was granted by the Ethics Committee of Assisted Reproductive Medicine at the Shanghai JiAi Genetics & IVF Institute (JIAI E2019-15). Written informed consent will be obtained from each woman before any study procedure is performed, according to good clinical practice. The results of this trial will be disseminated in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04371783.

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.

The impact of clinical and laboratory parameters on clinical pregnancy and live birth rates in fresh cycles: a retrospective study of 9608 high-quality cleavage-stage embryos

BACKGROUND

Evidence from the Istanbul consensus workshop suggests correlations between morphological parameters and embryo developments. 8-cell embryos are the best blastomere stage on day 3. No good quality evidence exists to support high-quality embryonic selection following blastulation and clinical outcomes. This study aimed to investigate the factors that affect blastocyst formation, blastocyst quality, and clinical outcomes of high-quality cleavage-stage embryos in fresh cycles.

METHODS

This study was a retrospective analysis of 9608 high-quality cleavage-stage embryos from 2987 couples between January 2017 to June 2021, namely 1520 embryos categorized as "812" (8-cell, grade 2, mild fragmentation), 2961 as "821" (8-cell, grade 2, mild asymmetry), 896 as "711" (7-cell, grade 1), and 517 as "911" (9-cell, grade 1) compared with 3714 embryos categorized as "811" (8-cell, grade 1). The primary outcomes were clinical pregnancy rate (CPR) and live birth rate (LBR). Blastulation rate (BR), available late blastocyst rate (ABR) and high-quality late blastocyst rate (HBR) were secondary outcome measures.

RESULTS

BR, ABR, and HBR had significant differences among the five groups (P < 0.001), while CPR and LBR were also significantly different in cleavage-stage fresh transfer (P < 0.01). The multivariable multilevel logistic regression analysis revealed a significant association between cell number, cell size, blastocyst development and clinical outcomes. For 7 to 9-cell highest-quality embryo, mild fragmentation and more blastomeres were more conducive to blastocyst formation and clinical outcomes. While cleavage-stage embryos developed into blastocysts, the negative impact of their initial morphology on clinical outcomes would be erased.

CONCLUSIONS

Our study firstly evaluated blastocyst development and clinical outcomes of high-quality cleavage-stage embryos in fresh cycles, with rankings of 811, 812, 911, 821, and 711. We found the initial morphological characteristics of the high-quality cleavage-stage embryos did not adversely impact clinical outcomes, even as they progressed to the blastocyst stage.

Effects of different progesterone levels on reproductive outcomes in assisted reproductive technologies: from molecular basis to treatment strategies

PURPOSE

The aim of this narrative review is to offer an overview about the role of progesterone levels on pregnancy outcome in patients undergoing assisted reproductive technologies (ARTs).

METHODS

A detailed computerized search of the literature was performed in the main electronic databases (MEDLINE, EMBASE, Web of Science) to determine the importance of elevated progesterone levels at different stages of the cycle for pregnancy rates in the in vitro fertilization (IVF) cycle. Our review also provides information on the differences between elevated progesterone levels and their interpretation in normal and in poorly responding women.

RESULTS

After careful evaluation, our search strategy yielded a total of 15 included articles, showing the possible factors that may have had an impact on the increased progesterone level before human chorionic gonadotropin (HCG) injection and the different thresholds above which the pregnancy rate was lower. Furthermore, increased progesterone on cycle day 2 or 3 could serve as a marker for increased progesterone in the late follicular phase, which is associated with a lower pregnancy rate.

CONCLUSION

Despite the literature data that support the negative effect of elevated progesterone on fresh cycles, due to lack of randomized controlled trials, the value of measuring progesterone in daily practice is questionable. Available evidence supports the detrimental effect of elevated progesterone in different subgroups of women, although there is still the need for defining different thresholds and durations of high progesterone exposure. The need for various thresholds for different cohorts of women, the inter-assay variability is making this decision harder.

Role and effectiveness of progestins in pituitary suppression during ovarian stimulation for assisted reproductive technology: a systematic review and a meta-analysis

INTRODUCTION

Despite the many unknowns about its exact mechanism, progesterone and progestins are being successfully used to prevent luteinizing hormone (LH) surge during ovarian stimulation for assisted reproductive technology (ART). We will review progestin primed ovarian stimulation (PPOS) protocols in comparison with gonadotropin releasing hormone (GnRH) analogues and each other.

EVIDENCE ACQUISITION

MEDLINE via PubMed; Cochrane Central Register of Controlled Trials (CENTRAL); Scopus; Web of Science were screened with keywords related to assisted reproductive technology, ovarian stimulation progesterone, GnRH analogue and progesterone in several combinations. Search period was from the date of inception of each database until 20 May 2022.

EVIDENCE SYNTHESIS

Live birth or ongoing pregnancy rate per embryo transfer (ET) was similar in PPOS and GnRH antagonist cycles (RR=1.16, 95% CI: 0.93-1.44). Clinical pregnancy rate per ET was likewise similar (RR=1.12, 95% CI: 0.92-1.37). Miscarriage rate per pregnancy was similar with PPOS and GnRH antagonists in autologous cycles (RR=1.01, 95% CI: 0.65-1.55). Pooled analyses showed similar live birth rate between progestins and short GnRH agonist protocols (RR=1.01, 95% CI: 0.49-2.09), however, clinical pregnancy rates per ET were significantly higher with progestins (RR=1.31, 95% CI: 1.06-1.62). Miscarriage rate per pregnancy was similar with progestins (RR=0.82, 95% CI: 0.55-1.21).

CONCLUSIONS

Progestins seem to be an efficient option for pituitary suppression during ovarian suppression, providing similar outcomes for stimulation and pregnancy. They can be especially beneficial for women for whom fresh ET is not considered.

The Ratio of Serum Progesterone (P4) to the Number of Follicles (P4/follicle) is a More Objective Parameter for Euploidy Rate as Compared to Systemic Progesterone Levels

Does the late follicular phase progesterone (P4) and the P4-to-follicle-ratio affect the ploidy state of the biopsied embryos? A retrospective observational study conducted at ART Fertility Clinics Abu Dhabi and Muscat, including all stimulation cycles performed between January 2015 and December 2019. In total, 975 cycles were considered for this study. Inclusion criteria were ovarian stimulation due to primary/secondary infertility, patient's age between 18 and 45 years, ICSI as fertilization method, and patients undergoing preimplantation genetic testing for aneuploidies (PGT-A). Patients with testicular sperm extraction (TESE) and warmed oocytes were excluded. Our results have shown that progesterone had no effect on the euploid rate (p = 0.371). However, when adding the ratio of P4 to the number of follicles that were bigger than 10 mm in the last scan, a negative effect on the euploid rate (p < 0.05) was observed. This study was able to show that the use of only P4 is unable to predict ploidy outcomes. However, by including the number of follicles > 10 mm, a clear association was observed between P4/Foll ratio and euploid rate per cycle. The use of both parameters could aid clinicians in their decision to trigger a patient or continue stimulation. Further prospective studies are warranted to confirm those results.

An appraisal of current embryo transfer strategies

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

Effects of reduced follicle-stimulating hormone dosage before human chorionic gonadotropin trigger on in vitro fertilization outcomes

OBJECTIVE

To determine whether a reduced dose of follicle-stimulating hormone (FSH) before human chorionic gonadotropin (hCG) trigger during ovarian stimulation can affect in vitro fertilization (IVF) outcomes.

METHODS

This study included 347 patients with a normal ovarian response who received a reduced dose of FSH before hCG trigger for 2-3 days (Group A) and 671 patients who did not receive a reduced dose (Group B) from a university-affiliated IVF center between January 2021 and December 2022. The primary endpoint was estrogen (E2) and progesterone (P) levels on the day of hCG trigger, fresh embryo transfer cycles, laboratory outcomes, and clinical outcomes between the two groups.

RESULTS

On the day of hCG trigger, Group A had significantly lower E2 and P levels than those in Group B (3454.95 ± 1708.14 pg/mL versus 3798.70 ± 1774.26 pg/mL, p = 0.003; and 1.23 ± 0.53 ng/mL versus 1.37 ± 0.59 ng/mL, p < 0.001, respectively). The proportion of patients with P levels ≥ 1.5 ng/mL was 22.48% in Group A compared to 34.58% in Group B (p < 0.001), while the proportion of patients with E2 ≥ 5000 pg/mL was 15.27% in Group A compared to 25.93% in Group B (p < 0.001). The fresh embryo-transfer cycle rate in Group A was higher than that in group B (54.47% and 32.64%, respectively; p < 0.001). Despite the reduction in FSH dosage, there were no significant differences between groups regarding the number of oocytes retrieved, total number of mature oocytes, normal fertilization rate, cleavage rate, Day 3 top-quality rate, implantation rate, pregnancy rate per cycle, and early pregnancy loss rate.

CONCLUSION

While a reduced dose of FSH prior to hCG trigger during ovarian stimulation did not significantly affect IVF outcomes, it was associated with lower E2 and P levels, resulting in fewer cycles with E2 ≥ 5000 pg/mL and P ≥ 1.5 ng/mL on the day of the hCG trigger.

One center experience with a personalized frozen-thawed embryo transfer in patients with recurrent implantation failure

PURPOSE

Displaced endometrial receptivity has been discussed as a possible cause of recurrent implantation failure in patients undergoing assisted reproductive technology. The aim of this study was to document our experience with the endometrial receptivity analysis in patients with recurrent implantation failure.

METHODS

This retrospective cohort study, conducted at the Fertility Centre of the University Hospital, Duesseldorf Germany, presents the results of the endometrial receptivity analysis in 67 patients with recurrent implantation failure and compares the clinical outcome between these 67 patients who underwent a personalized frozen-thawed embryo transfer guided by the results of the endometrial receptivity analysis and 32 patients with recurrent implantation failure who performed a standardized frozen-thawed embryo transfer.

RESULTS

The data analysis revealed a displaced endometrial receptivity in 73% (49/67) of all tested patients. Out of these patients, 24% (12/49) were early receptive, 74% (36/49) were pre-receptive, and 2% (1/49) were post-receptive. Comparison of pregnancy rate, clinical pregnancy rate, and live-birth rate between personalized (49%, 39%, 27%, respectively) and standardized embryo transfer (44%, 31%, 19%, respectively) reveals no statistically significant difference. In both groups, patients had an average of four unsuccessful embryo transfers.

CONCLUSION

In this cohort of patients with recurrent implantation failure, the endometrial receptivity analysis showed a high incidence of displaced endometrial receptivity. However, a personalized embryo transfer did not increase reproductive outcome. Displaced endometrial receptivity might not be the main cause for recurrent implantation failure in this cohort.

Nomogram for Predicting Live Birth after the First Fresh Embryo Transfer in Patients with PCOS Undergoing IVF/ICSI Treatment with the GnRH-Ant Protocol

Polycystic ovary syndrome (PCOS) is the leading cause of anovulatory infertility. A better understanding of factors associated with pregnancy outcomes and successful prediction of live birth after IVF/ICSI are important to guide clinical practice. This was a retrospective cohort study investigating live birth after the first fresh embryo transfer using the GnRH-ant protocol in patients with PCOS between 2017 and 2021 at the Reproductive Center of Peking University Third Hospital. A total of 1018 patients with PCOS were qualified for inclusion in this study. BMI, AMH level, initial FSH dosage, serum LH and progesterone levels on the hCG trigger day, and endometrial thickness were all independent predictors of live birth. However, age and infertility duration were not significant predictors. We developed a prediction model based on these variables. The predictive ability of the model was demonstrated well, with areas under the curve of 0.711 (95% CI, 0.672-0.751) and 0.713 (95% CI, 0.650-0.776) in the training cohort and validation cohort, respectively. Additionally, the calibration plot showed good agreement between the prediction and the observation (p = 0.270). The novel nomogram could be helpful for clinicians and patients in clinical decision-making and outcome evaluation.

Association between the number of oocytes and cumulative live birth rate: A systematic review

The available literature is controversial regarding the association between the number of oocytes retrieved and the cumulative live birth rate (CLBR). Although some authors report a continuous increase in the CLBR with the number of oocytes retrieved, others have found a plateau. A systematic review was conducted, including all eligible studies published until June 2022, to determine the optimal number of oocytes retrieved to maximize the CLBR. We found a positive association between the number of oocytes and the CLBR. However, this association varies according to patients' age. While in patients younger than 35 years, little benefit is derived from increasing the number of oocytes above 25-30, in patients older than 35 years, the number of oocytes seems to improve the CLBR until the extreme of reproductive age is reached. In women aged 44 years or older, the CLBR will be consistently low, independent of the number of oocytes retrieved.

Freeze-all embryos during treatment with assisted reproduction: Health economic aspects

Assisted reproductive technologies are evolving, with the most recent example being the introduction of the freeze-all policy during which a fresh embryo transfer does not take place and all embryos of good quality are cryopreserved to be used in future frozen embryo transfers. As the freeze-all policy is becoming more prevalent, it is important to review the economic aspects of this approach, along with considerations of efficacy and safety, and the role of emerging freeze-all-specific ovarian stimulation strategies. Based on the available evidence, the freeze-all policy presents distinct clinical advantages, particularly for high responders. Available health economic evaluations are limited. Two good-quality cost-effectiveness analyses based on randomized controlled trials suggest that the freeze-all strategy is unlikely to be cost-effective in non-polycystic ovarian syndrome (non-PCOS), normally responding patients. However, the cost-effectiveness of the freeze-all strategy in different populations of patients and in different settings has not been evaluated, nor has the clinical and economic efficacy of modern freeze-all-specific ovarian stimulation protocols that are likely to simplify treatment and make it more affordable for patients. Economic evaluations that incorporate good practice health technology assessment (HTA) methods are needed to compare freeze-all with conventional embryo transfer strategies. Furthermore, future research should address the unique limitation of traditional HTA methods in valuing a life conceived through fertility treatment.

Clinical pregnancy outcomes prediction in vitro fertilization women based on random forest prediction model: A nested case-control study

The present study aimed to analyze the risk factors influencing the in vitro fertilization embryo transfer (IVF-ET) pregnancy and to construct a prediction model for clinical pregnancy outcome in patients receiving IVF-ET based on the predictors. In this nested case-control study, the data of 369 women receiving IVF-ET were enrolled. Univariate and multivariate Logistic regression analyses were conducted to identify the potential predictors. Ten-fold cross validation method was used to validate the random forest model for predicting the clinical pregnancy. The receiver operating characteristic curve was drawn to evaluate the prediction ability of the model. The importance of variables was shown according to Mean Decrease Gini. The data delineated that age (odds ratio [OR]= 1.093, 95% confidence interval [CI]: 1.036-1.156, P = .0010), body mass index (BMI) (OR = 1.094, 95%CI: 1.021-1.176, P = .012), 3 cycles (OR = 0.144, 95%CI: 0.028-0.534, P = .008), hematocrit (HCT) (OR = 0.865, 95% CI: 0.791-0.943, P = .001), luteinizing hormone (LH) (OR = 0.678, 95%CI: 0.549-0.823, P < .001), progesterone (P) (OR = 2.126, 95%CI: 1.112-4.141, P = .024), endometrial thickness (OR = 0.132, 95%CI: 0.034-0.496, P = .003) and FSH (OR = 1.151, 95%CI: 1.043-1.275, P = .006) were predictors associated with the clinical pregnancy outcome of patients receiving IVF-ET. The results might provide a novel method to identify patients receiving IVF-ET with a high risk of poor pregnancy outcomes and provide interventions in those patients to prevent the occurrence of poor pregnancy outcomes.

Elevated serum progesterone levels on the hCG trigger day have a negative impact on the live birth rate in the first fresh IVF-ET cycle

To investigate whether there is a relationship between elevated serum progesterone (PROG) on the hCG trigger day and the live birth rate (LBR) in IVF/ICSI cycles, the retrospective analysis was carried out from the patients undergoing the first ART cycles throughout 2016. The PROG levels were measured on the hCG trigger day. The LBR, clinical pregnancy rate (CPR), implantation rate (IR) and other parameter rate values were compared among the three different PROG elevations. A total of 2550 IVF/ICSI cycles fulfilling all the inclusion and exclusion criteria were selected. Finally, three groups [PROG <0.40 ng/mL, 0.40 ≤ PROG < 1.5 ng/mL, PROG ≥ 1.5 ng/mL] were categorised based on the serum PROG levels. LBR, CPR and IR declined as the PROG value increased, while there was no difference in the embryo utilisation rates. Serum PROG levels on the day of hCG administration were negatively associated with the LBR, even in ETs with a good prognosis.Impact StatementWhat is already known on this subject? The clinical effects of PROG are still controversial. Some studies have confirmed that there was not too much association between premature elevation of PROG and live birth, some are still convincing that there is a negative correlation and will result in ART cycles of pregnancy and LBR reduction.What do the results of this study add? Our data substantiated that the high serum PROG level had the lowest LBR, IR and CPR, but the embryo utilisation rate may not have too much to do with the elevated PROG.What are the implications of these findings for clinical practice and/or further research? This study further strengthens the negative impact of elevated PROG levels on pregnancy outcomes, and suggests that frozen thawed embryo transfer appears to be a reasonable and advantageous approach for this subset of patients.

Is there an optimal window of time for transferring single frozen-thawed euploid blastocysts? A cohort study of 1170 embryo transfers

STUDY QUESTION

Is there an optimal window of time when the transfer of single frozen-thawed euploid blastocysts is associated with a maximal live birth rate (LBR)?

SUMMARY ANSWER

Performing a single frozen-thawed euploid blastocyst transfer at 160 ± 4 h post-hCG trigger in modified-natural frozen-thawed embryo transfer (FET) cycles was independently associated with a higher LBR as compared to transfers outside this window; however, in natural FET cycles, LBRs were comparable across a wider range of time intervals.

WHAT IS KNOWN ALREADY

There is compelling evidence for maintaining embryo-endometrial synchrony to optimize clinical outcomes following FETs, which could potentially be achieved by matching the transfer time of an embryo post-ovulation to its developmental age post-oocyte retrieval. For modified-natural cycles, ovulation is widely accepted to occur ∼40 h following the hCG trigger, whilst ovulation following spontaneous LH surge onset is thought to vary from 24 to 56 h.

STUDY DESIGN, SIZE, DURATION

This is a multicentered retrospective cohort study analyzing 1170 single frozen-thawed euploid blastocyst transfers following trophectoderm biopsy and preimplantation genetic testing (PGT) between May 2015 and February 2019. Limiting the analysis to single euploid embryo transfers allowed for a more accurate estimation of the endometrial synchrony factor by controlling for the developmental stage of the embryo (full blastocyst or more advanced) and its genetic composition. LBR per FET was the primary outcome measure.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients underwent natural or gonadotrophin-induced preparation of the endometrium, with serial serum oestradiol, LH and progesterone measurements. Optimally timed transfers were predefined as those conducted 120 ± 4 h post-ovulation since biopsy and subsequent cryopreservation of full blastocysts which is usually performed at 116-124 h post-oocyte retrieval. This was considered the equivalent of 160 ± 4 h post-hCG trigger in modified-natural cycles (n = 253), as ovulation was assumed to occur ∼40 h after the hCG trigger. For natural cycles (n = 917), this was also considered to be, on average, 160 ± 4 h post the spontaneous LH surge. Thus, study groups were determined as those with optimal timing or not, and additional exploratory and subgroup analyses were performed, varying the time window in terms of onset and width, both overall and per endometrial preparation protocol. Statistical analysis was performed using the generalized estimating equations (GEE) framework to control for the clustered nature of the data while adjusting for potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, LBRs were significantly higher when the transfer had been performed at 160 ± 4 h post-hCG trigger or LH surge onset compared to when it had been performed outside this window (44.7% vs 36.0%; P = 0.008). A multivariable regression GEE model including the cycle type (natural versus modified-natural), previtrification embryo quality (top versus good quality), embryo stage (fully hatched versus hatching or earlier blastocyst), vitrification day (D5 versus D6) and survival rate (>90% versus <90%) as covariates, confirmed that, overall, embryo transfers conducted 160 ± 4 h post-hCG trigger or LH surge onset (the assumed equivalent of 120 ± 4 h post-ovulation) were associated with a significantly higher LBR (relative risk (RR) 1.21, 95% CI 1.04-1.41). Subgroup exploratory analyses per endometrial preparation protocol demonstrated that these findings were primarily present in the modified-natural cycle group (RR 1.52, 95% CI 1.15-1.99), whilst the natural cycle group showed comparable LBRs across a wider range of time intervals. Moreover, the overall LBR for the natural group (36.8%; 95% CI 33.7-39.9%) was lower than that of the modified-natural group (41.3%; 95% CI 35.4-47.1%), suggesting that there likely remains a greater potential to further optimize the timing of natural cycle embryo transfers.

LIMITATIONS, REASONS FOR CAUTION

As with all retrospective studies, the presence of residual unknown bias cannot be excluded. Additionally, patients included in this study were a selected group who underwent PGT for specific reasons and hence the results obtained might not be directly applicable to the general population or embryos that have not undergone embryo biopsy. Furthermore, the criteria utilized to interpret hormonal data from natural cycles were specifically adopted for the present study and need to be validated in further studies.

WIDER IMPLICATIONS OF THE FINDINGS

The results of this study highlight the significance of embryo-endometrial synchrony for the optimization of frozen embryo transfer outcome. However, it also clearly supports that the implantation window is in most cases wide and the achievement of live birth is possible with relatively high success rates even outside the optimal window of 160 ± 4 h post-trigger for modified-natural cycles and across a range of time intervals for natural cycles. Additionally, this study suggests that implantation rates could be further optimized in natural cycles by improving methods of assessing embryo-endometrial synchrony.

STUDY FUNDING/COMPETING INTEREST(S)

C. V. is supported by a National Health and Medical Research Council Early Career Fellowship (GNT1147154). No other funding was received for this study and there are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

The impact of different endometrial preparation protocols on obstetric and neonatal complications in frozen-thawed embryo transfer: a retrospective cohort study of 3,458 singleton deliveries

BACKGROUND

Frozen-thawed embryo transfer (FET) is thought to be associated with obstetric and neonatal complications after in vitro fertilization/intracytoplasmic single sperm injection (IVF/ICSI) treatment. The study aimed to determine whether the endometrial preparation protocol is an influencing factor for these complications.

METHODS

We conducted a retrospective cohort study of 3,458 women who had singleton deliveries after IVF/ICSI-FET treatment at the Centre for Reproductive Medicine of Shanghai First Maternity and Infant Hospital between July 2016 and April 2021. The women were divided into three groups according to the endometrial preparation protocols: 2,029 women with programmed cycles, 959 with natural cycles, and 470 with minimal ovarian stimulation cycles. The primary outcomes were the incidence rates of obstetric and neonatal complications, namely, hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), intrahepatic cholestasis of pregnancy (ICP), placenta previa, preterm rupture of membranes (PROM), preterm delivery, postpartum haemorrhage, large for gestational age (LGA), small for gestational age (SGA), and macrosomia.

RESULTS

After adjustments for confounding variables by multivariate logistic regression analysis, the results showed that programmed cycles had an increased risk of HDP (aOR = 1.743; 95% CI, 1.110-2.735; P = 0.016) and LGA (aOR = 1.269; 95% CI, 1.011-1.592; P = 0.040) compared with natural cycles. Moreover, programmed cycles also increased the risk of LGA (aOR = 1.459; 95% CI, 1.083-1.965; P = 0.013) but reduced the risk of SGA (aOR = 0.529; 95% CI, 0.348-0.805; P = 0.003) compared with minimal ovarian stimulation cycles. There were no significant differences between natural cycles and minimal ovarian stimulation cycles.

CONCLUSIONS

During IVF/ICSI-FET treatment, the risk of HDP and LGA was increased in women with programmed cycles. Therefore, for patients with thin endometrium, irregular menstruation or no spontaneous ovulation, minimal ovarian stimulation cycles may be a relatively safer option than programmed cycles.

The effect of polymorphisms in FSHR gene on late follicular phase progesterone and estradiol serum levels in predicted normoresponders

STUDY QUESTION

Does the presence of FSHR single-nucleotide polymorphisms (SNPs) affect late follicular phase progesterone and estradiol serum levels in predicted normoresponders treated with rFSH?

SUMMARY ANSWER

The presence of FSHR SNPs (rs6165, rs6166, rs1394205) had no clinically significant impact on late follicular phase serum progesterone and estradiol levels in predicted normoresponders undergoing a GnRH antagonist protocol with a fixed daily dose of 150 IU rFSH.

WHAT IS KNOWN ALREADY

Previous studies have shown that late follicular phase serum progesterone and estradiol levels are significantly correlated with the magnitude of ovarian response. Several authors have proposed that individual variability in the response to ovarian stimulation (OS) could be explained by variants in FSHR. However, so far, the literature is scarce on the influence of this genetic variability on late follicular phase steroidogenic response. Our aim is to determine whether genetic variants in the FSHR gene could modulate late follicular phase serum progesterone and estradiol levels.

STUDY DESIGN, SIZE, DURATION

In this multicenter multinational prospective study conducted from November 2016 to June 2019, 366 patients from Vietnam, Belgium and Spain (166 from Europe and 200 from Asia) underwent OS followed by oocyte retrieval in a GnRH antagonist protocol with a fixed daily dose of 150 IU rFSH. All patients were genotyped for 3 FSHR SNPs (rs6165, rs6166, rs1394205) and had a serum progesterone and estradiol measurement on the day of trigger.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Included patients were predicted normal responder women <38 years old undergoing their first or second OS cycle. The prevalence of late follicular phase progesterone elevation (PE), as well as mean serum progesterone and estradiol levels on the day of trigger were compared between the different FSHR SNPs genotypes. PE was defined as >1.50 ng/ml.

MAIN RESULTS AND THE ROLE OF CHANCE

The overall prevalence of PE was 15.8% (n = 58). No significant difference was found in the prevalence of PE in Caucasian and Asian patients (17.5% versus 14.5%). Estradiol levels on the day of trigger and the number of retrieved oocytes were significantly higher in patients with PE (4779 ± 6236.2 versus 3261 ± 3974.5 pg/ml, P = 0.003, and 16.1 ± 8.02 versus 13.5 ± 6.66, P = 0.011, respectively). Genetic model analysis, adjusted for patient age, body mass index, number of retrieved oocytes and continent (Asia versus Europe), revealed a similar prevalence of PE in co-dominant, dominant and recessive models for variants FSHR rs6166, rs6165 and rs1394205. No statistically significant difference was observed in the mean late follicular phase progesterone serum levels according to the genotypes of FSHR rs6166 (P = 0.941), rs6165 (P = 0.637) and rs1394205 (P = 0.114) in the bivariate analysis. Also, no difference was found in the genetic model analysis regarding mean late follicular phase progesterone levels across the different genotypes. Genetic model analysis has also revealed no statistically significant difference regarding mean estradiol levels on the day of trigger in co-dominant, dominant and recessive models for variants FSHR rs6166, rs6165 and rs1394205. Haplotype analysis revealed a statistically significant lower estradiol level on the day of trigger for rs6166/rs6165 haplotypes GA, AA and GG when compared to AG (respectively, estimated mean difference (EMD) -441.46 pg/ml (95% CI -442.47; -440.45), EMD -673.46 pg/ml (95% CI -674.26; -672.67) and EMD -582.10 pg/ml (95% CI -584.92; -579.28)). No statistically significant differences were found regarding the prevalence of PE nor late follicular phase progesterone levels according to rs6166/rs6165 haplotypes.

LIMITATIONS, REASONS FOR CAUTION

Results refer to a population of predicted normal responders treated with a normal/low fixed dose of 150 IU rFSH throughout the whole OS. Consequently, caution is needed before generalizing our results to all patient categories.

WIDER IMPLICATIONS OF THE FINDINGS

Based on our results, FSHR SNPs rs6165, rs6166 and rs1394205 do not have any clinically significant impact neither on late follicular phase serum progesterone nor on estradiol levels in predicted normal responders. These findings add to the controversy in the literature regarding the impact of individual genetic susceptibility in response to OS in this population.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by an unrestricted grant by Merck Sharp & Dohme (MSD, IISP56222). N.P.P. reports grants and/or personal fees from MSD, Merck Serono, Roche Diagnostics, Ferring International, Besins Healthcare, Gedeon Richter, Organon, Theramex and Institut Biochimique SA (IBSA). C.A. reports conference fees from Merck Serono, Medea and Event Planet. A.R.N., C.B., C.S., P.Q.M.M., H.T., C.B., N.L.V., M.T.H. and S.G. report no conflict of interests related to the content of this article.

TRIAL REGISTRATION NUMBER

NCT03007043.

Pro: Fresh versus frozen embryo transfer. Is frozen embryo transfer the future?

Embryo cryopreservation has been an integral part of ART for close to 40 years and vitrification has boosted overall ART efficacy and safety. Recently, there has been a vivid scientific discussion on whether elective cryopreservation of all embryos (freeze-all) should be pursued for most patients, with a fresh embryo transfer taking place only in selected cases. In terms of efficacy, the available evidence suggests that the freeze-all strategy leads to higher live birth rates after the first embryo transfer compared to the conventional strategy in high responders, while there is no difference in normal responders. There is no evidence to suggest that the freeze-all strategy is inferior to the conventional strategy of fresh transfer when comparing cumulative live birth rates using data from all available randomized controlled trials. The incidence of ovarian hyperstimulation syndrome is significantly reduced in the freeze-all policy. However, regarding obstetric complications and neonatal outcomes, the evidence suggests that each strategy is associated with certain risks and, therefore, there is no approach that could be unequivocally accepted as safer. Similarly, limited evidence does not support the notion that patients would be universally against freeze-all owing to the inevitable delay in pregnancy achievement. Finally, the cost-effectiveness of freeze-all is likely to vary in different settings and there have been studies supporting that this policy can be, under certain conditions, cost-effective. Adoption of the freeze-all policy can also allow for more flexible treatment strategies that have the potential to increase efficacy, reduce cost and make treatment easier for patients and clinics. Importantly, freeze-all does not require the use of any experimental technologies, further training of personnel or the costly acquisition of new equipment. For these reasons, transitioning to the freeze-all policy for most patients appears to be the next logical step in ART.

Impact of blood levels of progesterone on the day of ovulation onset on clinical, laboratory and reproductive parameters of young patients undergoing assisted reproduction: a cross-sectional study

Objective:

To assess whether there is an association between the level of progesterone on the day of administration of human chorionic gonadotropin and clinical and laboratory characteristics, in addition to the results of in vitro fertilization of patients with a good prognosis.

Methods:

A cross-sectional study comprising 103 women who underwent intracytoplasmic sperm injection treatment, between November 2009 and May 2015, aged ≤35 years, with no comorbidities, with fresh embryo transfer. Data were collected from patient medical records.

Results:

There was a weak positive correlation between the level of progesterone on the day of human chorionic gonadotropin and the number of follicles larger than 14mm (ß=0.02, p=0.001), retrieved oocytes (ß=0.01, p=0.01) and oocytes in metaphase II (MII) (ß=0.02, p=0.02); that is, the increase in progesterone level has a slight association with increased values of these variables. Body mass index was inversely correlated with progesterone level on the day of human chorionic gonadotropin (ß=-0.01, p=0.02). No association was found between the level of progesterone on the day of human chorionic gonadotropin and the protocols used for controlled ovarian stimulation, quality of transferred embryos and the pregnancy rate.

Conclusion:

There is an association between the value of progesterone on the day of human chorionic gonadotropin administration with body mass index, number of follicles larger than 14mm, number of retrieved oocytes and oocytes in metaphase II. Unlike embryo quality and pregnancy rate, which do not have a statistically significant relation with this value in the population studied.

Effect of slightly elevated progesterone on hCG trigger day on clinical pregnancy rate in GnRH-ant IVF/ICSI cycles

Background

It was been agreed that significantly elevated progesterone level on the hCG trigger day have detrimental effect on clinical outcomes in IVF/ICSI cycles. However, few studies explored whether slightly elevated progesterone level also same impact on clinical outcomes.

Methods

We retrospectively studies the effect of slightly elevated progesterone level on outcomes of IVF/ICSI in GnRH-ant cycles. Propensity score matching was used to confounding variables. The women were divided into two groups according to the progesterone level: Group 1: < 1.0 ng/ml; Group 2: 1.0 ng/ml–1.5 ng/ml. Then compare the clinical pregnancy rate (CPR) between the two groups.

Result

A total of 847 IVF/ICSI cycles were included in the present study. The average CPR per transfer cycle was 51.7%. CPR of group 1 was 55.22%, significantly higher than that of group 2 (40.66%, P = 0.013). Progesterone level on the day of hCG injection was further evaluated at threshold increments of 0.1 ng/ml, and the CPR was decreased dramatically once the progesterone level higher than 1.4 ng/ml.

Conclusion

The slight elevation progesterone level on the hCG trigger day may have a negative effect on the clinical pregnancy in GnRH-ant cycles. In the case of progesterone > 1.4 ng/ml on the hCG injection day, freeze-all strategy was recommended.

Summary

The present retrospective study aimed to evaluate the effect of slightly elevated progesterone (1.0 ng/ml ~ 1.5 ng/ml) on outcomes of IVF/ICSI in GnRH-ant cycles. Slightly elevated progesterone level leaded to significant lower clinical pregnancy rate (CPR) that that of group with normal progesterone level (40.66% vs. 55.22%, P = 0.013). The CPR was decreased dramatically once the progesterone level higher than 1.4 ng/ml. So slightly elevated progesterone level on the trigger day may have a negative effect on the clinical pregnancy in GnRH-ant cycles. In the case of progesterone > 1.4 ng/ml on the hCG injection day, freeze-all strategy was recommended.

Letrozole Supplementation and the Increased Risk of Elevated Progesterone Levels on Trigger Day

Although using letrozole (LE) during in vitro fertilisation and intracytoplasmic sperm injection (IVF/ICSI) has many advantages, it remains unclear whether LE induces an increase in progestogen during the late follicular phase. The objective of this study was to investigate whether progesterone levels increased under antagonist protocols supplemented with LE on the trigger day using a retrospective cohort study. The study included 1,133 women who underwent IVF/ICSI cycles from January 2018 to June 2020. After propensity score matching (PSM) for baseline characteristics, 266 patients with gonadotropin-releasing hormone-antagonist (GnRH-ant) were matched to 266 patients with letrozole + GnRH-ant (LE GnRH-ant) (PSM 1 cohort), and 283 patients with gonadotropin-releasing hormone-agonist (GnRH-a) were matched to 283 patients with LE GnRH-ant (PSM 2 cohort). In the PSM 1 cohort, patients in the LE GnRH-a group presented higher progesterone levels (1.22 ± 0.95 ng/mL vs 0.86 ± 0.60 ng/mL, P < 0.001), with a higher proportion of patients with progesterone level > 1.5 ng/mL (24.81% vs 7.52%, P < 0.001). In PSM 2 cohort, patients in the LE GnRH-a group presented higher progesterone levels on trigger day (1.23 ± 0.91 ng/mL vs 0.98 ± 0.61 ng/mL, P < 0.001), with a higher proportion of patients with progesterone level > 1.5 ng/mL (25.45% vs 12.70%, P < 0.001). In the PSM 1 cohort, progesterone levels on the trigger day increased by 0.05 ng/mL, with an increase in every retrieved oocyte in the LE GnRH-ant group (β 0.05 ng/mL [95% CI 0.04, 0.06], P < 0.001), whereas an increase of 0.02 ng/mL was observed in the GnRH-ant group (β 0.02 ng/mL [95% CI 0.01, 0.03], P < 0.001), with P for interaction being 0.0018. In the PSM 2 cohort, progesterone levels on the trigger day increased by 0.05 ng/mL with an increase in every retrieved oocyte in the LE GnRH-ant group (β 0.05 ng/mL [95% CI 0.04, 0.06], P < 0.001), whereas an increase of 0.02 ng/mL was observed in the GnRH-a group (β 0.02 ng/mL [95% CI 0.01, 0.03], P < 0.001), with P for interaction being 0.0002. LE supplementation on the antagonist protocols may increase progesterone levels in the late follicular stage.

Effect of serum progesterone levels on hCG trigger day on pregnancy outcomes in GnRH antagonist cycles

OBJECTIVE

The present study analyzed the effect of hCG trigger day progesterone (P) levels on the live birth rate (LBR) in the gonadotropin-releasing hormone (GnRH) antagonist protocol.

MATERIALS AND METHODS

This study was a single-center retrospective study. In vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles performed from January 2017 to December 2020 were included in the analysis. This study included people with a normal ovarian response to fresh embryo transfer of GnRH antagonist protocols. All cycles were divided into 2 groups by P level on the day of human chorionic gonadotropin (hCG) trigger, P<1.0 ng/ml and P≥1.0 ng/ml. The primary outcome measure was LBR.

RESULT

A total of 867 cycles with P<1.0 ng/ml and 362 cycles with P≥1.0 ng/ml were included in the analysis. The clinical pregnancy rate (CPR) was higher in the P<1.0 ng/ml group than the P≥1.0 ng/ml group (44.9% vs. 37.6%, P=0.02). The early spontaneous abortion rate was comparable between the groups (14.4% vs. 14.7%, P=0.93). For live birth, the rate for the P<1.0 ng/ml group was 35.3%, which was significantly higher than the 29.0% in the P≥1.0 ng/ml group (P=0.03). After binary logistic regression analysis, the P level on the hCG trigger day (adjusted odds ratio=0.74, 95% CI=0.55-0.99, P=0.04) was an independent risk factor for LBR. For the P level on the hCG trigger day, the LBR was lower in the P≥1.0 ng/ml group compared to the P<1.0 ng/ml group.

CONCLUSION

For normal ovarian response patients using the GnRH antagonist protocol, serum P≥1.0 ng/ml on the hCG trigger day resulted in a lower LBR than the P<1.0 ng/ml group. When P≥1.0 ng/ml, whole embryo freezing may be considered.

GVBD rate is an independent predictor for pregnancy in ICSI patients with surplus immature oocytes

INTRODUCTION

It was reported that there were still up to 30% immature retrieved oocyte at germinal vesicle (GV) or metaphase I (MI) stage. Whether the spontaneous maturity competency of immature oocytes associated to the clinical outcome of in vitro fertilization (IVF) cycles remains unclear and unexplored. This study aimed to investigate how the oocyte developmental parameters in in vitro maturation (IVM) affect clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles.

METHODS

This retrospective cohort study included couples undergoing ICSI in a university-affiliated hospital. Surplus immature oocytes during ICSI were collected and cultured in vitro. The numbers of germinal vesicle (GV) oocytes undergoing GV breakdown (GVBD) and polar body 1 extrusion within 24 h culture were recorded. The main outcome measurements were demographic baselines and oocyte developmental parameters in IVM associated with pregnancy outcomes.

RESULTS

A total of 191 couples were included with an overall GVBD rate of 63.7% (327/513) and oocyte maturation rate of 46.8% (240/513). 53.4% (102/191) of them had embryos transferred freshly, which originated from metaphase II oocytes that matured spontaneously in vivo, and 60.8% (62/102) got pregnant. Among factors with a P-value < 0.2 in univariate logistic regression analyses of pregnancy correlation, GVBD rate (OR 3.220, 95% CI 1.060-9.782, P=0.039) and progesterone level on human chorionic gonadotropin (HCG) day (OR 0.231, 95% CI 0.056-0.949, P=0.042) remained significant in the multivariate model. The area under the curve (AUC) of the predictive nomogram was 0.729 (95% CI 0.632-0.826) with an acceptable calibration. Moreover, decision curve analyses illustrated the superior overall net benefit of models that included the GVBD rate in clinical decisions within a wide range of threshold probabilities.

CONCLUSION

In conclusion, GVBD rate and progesterone level on HCG day may be associated with pregnancy outcomes in infertile couples during the regular ICSI procedure. An elevated GVBD rate within 24 h may greatly increase the likelihood of pregnancy in infertile couples during ICSI. This preliminary study may optimize clinical pregnancy prediction, which provides support in decision-making in clinical practice.

DUAL TRIGGER STRATEGY AFTER CONTROLLED STIMULATION INTRAUTERINE INSEMINATION CYCLE DID NOT INFLUENCE THE PREGNANCY OUTCOME COMPARED WITH STANDARD HCG TRIGGER ONLY PROTOCOL

OBJECTIVE

The aim: A prospective randomized comparative study was conducted to investigate the effect of dual trigger, using gonadotropin releasing hormone agonist with human chorionic gonadotropin (hCG) versus hCG alone, for ovulation trigger in controlled ovarian stimulation intrauterine insemination (IUI) cycle on pregnancy outcome.

PATIENTS AND METHODS

Materials and methods: Ninety women were randomly allocated into equal groups to trigger ovulation for IUI cycle using either method; IUI was performed following 36-42 hours post triggering. Luteinizing hormone (LH) and progesterone levels were measured at insemination day.

RESULTS

Results: The baseline of demographic and clinical characteristics of both groups was similar. Progesterone level was higher in dual trigger group than in hCG alone group (1.61 versus 0.71 ng/mL, P≤0.0001); while LH level was lower in dual trigger group (19.35 versus 24.51 IU/L, P≤0.014). Furthermore, LH level at the day of IUI was higher in pregnant women than in non-pregnant (27.9 versus 20 IU/L, P≤0.007).

CONCLUSION

Conclusions: Pregnancy rate was equivalent in both groups. More intensive investigation is required to study the efficacy of the dual trigger in IUI cycle.

Progesterone elevation on the day of oocyte retrieval and live birth rate after in vitro fertilisation treatment

The objective of this study was to evaluate if progesterone elevation (PE) on the day of oocyte retrieval is associated with IVF outcome. A prospective cohort study of 400 IVF-ICSI cycles, with fresh embryo transfer on day 2-3 was performed. We proposed a serum progesterone (P) level on percentile (p) 90 as a threshold.Pregnancy rates were not affected, however there were more miscarriages (25.7% vs 43.8%) and lower live birth rate (LBR) (28% vs 23.1%) in the PE group (not statistically significant). We also found a positive correlation between P levels and retrieved and mature oocytes, total embryos, and good quality embryos. This is the first study to analyse LBR based on P levels on the day of oocyte retrieval. PE is not associated with the IVF outcome, but there is a trend to lower ongoing pregnancy rate and LBR and more miscarriages. Our results also show that P levels have no negative effects on oocyte and embryo quality.Impact statementWhat is already known on this subject? The influence of PE during IVF cycle on pregnancy rates remains controversial.What do the results of this study add? This is the first study to analyse LBR based on P levels on the day of oocyte retrieval.What are the implications of these findings for clinical practice and/or further research? We demonstrated that pregnancy rates were not affected by PE at oocyte retrieval, but there is a trend to lower ongoing pregnancy rate and LBR and more miscarriages. Randomised controlled trials are needed to offer more evidence of these relationships.

Impact of letrozole co-treatment during ovarian stimulation with gonadotrophins for IVF: a multicentre, randomized, double-blinded placebo-controlled trial

STUDY QUESTION

Does letrozole co-treatment during ovarian stimulation with gonadotrophins for IVF reduce the proportion of women with premature progesterone levels above 1.5 ng/ml at the time of triggering final oocyte maturation?

SUMMARY ANSWER

The proportion of women with premature progesterone above 1.5 ng/ml was not significantly affected by letrozole co-treatment.

WHAT IS KNOWN ALREADY

IVF creates multiple follicles with supraphysiological levels of sex steroids interrupting the endocrine milieu and affects the window of implantation. Letrozole is an effective aromatase inhibitor, normalizing serum oestradiol, thereby ameliorating some of the detrimental effects of IVF treatment.

STUDY DESIGN, SIZE, DURATION

A randomized, double-blinded placebo-controlled trial investigated letrozole intervention during stimulation for IVF with FSH. The trial was conducted at four fertility clinics at University Hospitals in Denmark from August 2016 to November 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A cohort of 129 women with expected normal ovarian reserve (anti-Müllerian hormone 8-32 nmol/l) completed an IVF cycle with fresh embryo transfer and received co-treatment with either 5 mg/day letrozole (n = 67) or placebo (n = 62), along with the FSH. Progesterone, oestradiol, FSH, LH and androgens were analysed in repeated serum samples collected from the start of the stimulation to the mid-luteal phase. In addition, the effect of letrozole on reproductive outcomes, total FSH consumption and adverse events were assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

The proportion of women with premature progesterone >1.5 ng/ml was similar (6% vs 0% (OR 0.0, 95% CI [0.0; 1.6], P = 0.12) in the letrozole versus placebo groups, respectively), whereas the proportion of women with mid-luteal progesterone >30 ng/ml was significantly increased in the letrozole group: (59% vs 31% (OR 3.3, 95% CI [1.4; 7.1], P = 0.005)). Letrozole versus placebo decreased oestradiol levels on the ovulation trigger day by 68% (95% CI [60%; 75%], P < 0.0001). Other hormonal profiles, measured as AUC, showed the following results. The increase in LH in the letrozole group versus placebo group was 38% (95% CI [21%; 58%], P < 0.0001) and 34% (95% CI [11%; 61%], P = 0.006) in the follicular and luteal phases, respectively. In the letrozole group versus placebo group, testosterone increased by 79% (95% CI [55%; 105%], P < 0.0001) and 49% (95% CI [30%; 72%], P < 0.0001) in the follicular and luteal phases, respectively. In the letrozole group versus placebo group, the increase in androstenedione was by 85% (95% CI [59%; 114%], P < 0.0001) and 69% (95% CI [48%; 94%], P < 0.0001) in the follicular and luteal phases, respectively. The ongoing pregnancy rate was similar between the letrozole and placebo groups (31% vs 39% (risk-difference of 8%, 95% CI [-25%; 11%], P = 0.55)). No serious adverse reactions were recorded in either group. The total duration of exogenous FSH stimulation was 1 day shorter in the intervention group, significantly reducing total FSH consumption (mean difference -100 IU, 95% CI [-192; -21], P = 0.03).

LIMITATIONS, REASONS FOR CAUTION

Late follicular progesterone samples were collected on the day before and day of ovulation triggering for patient logistic considerations, and the recently emerged knowledge about diurnal variation of progesterone was not taken into account. The study was powered to detect hormonal variations but not differences in pregnancy outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

Although the use of letrozole has no effect on the primary outcome, the number of women with a premature increase in progesterone on the day of ovulation triggering, the increased progesterone in the mid-luteal phase due to letrozole may contribute to optimizing the luteal phase endocrinology. The effect of letrozole on increasing androgens and reducing FSH consumption may be used in poor responders. However, the effect of letrozole on implantation and ongoing pregnancy rates should be evaluated in a meta-analysis or larger randomized controlled trial (RCT).

STUDY FUNDING/COMPETING INTEREST(S)

Funding was received from EU Interreg for ReproUnion and Ferring Pharmaceuticals, and Roche Diagnostics contributed with assays. N.S.M. and A.P. have received grants from Ferring, Merck Serono, Anecova and Gedeon Richter, and/or personal fees from IBSA, Vivoplex, ArtPred and SPD, outside the submitted work. The remaining authors have no competing interests.

TRIAL REGISTRATION NUMBERS

NCT02939898 and NCT02946684.

TRIAL REGISTRATION DATE

15 August 2016.

DATE OF FIRST PATIENT’S ENROLMENT

22 August 2016.

The efficiency of progesterone/estradiol and progesterone/follicle ratio without elevated trigger-day progesterone levels on the reproductive outcomes of GnRH antagonist IVF/ICSI cycles

AIM

To assess the predictive value of serum progesterone/estradiol (P/E₂) and serum progesterone/follicle (P/F) ratios on the reproductive outcomes of women without elevated trigger-day progesterone levels undergoing GnRH-antagonist IVF (in vitro fertilization)/ICSI (intracytoplasmic sperm injection) cycles.

MATERIALS AND METHODS

This was a retrospective cohort study in a university teaching hospital conducted between January 2017 and December 2019. Couples who underwent assisted reproduction cycles were evaluated. Initially, 978 cycles were evaluated and only GnRH antagonist cycles (n = 505) without elevated trigger-day progesterone levels were analyzed after respecting exclusion criteria.

RESULTS

A total of 505 cycles were analyzed after the exclusion criteria were met. The clinical pregnancy rate, ongoing pregnancy rate, and live birth rate were 45.5%, 30.9%, and 27.8%, respectively. Cutoff values of P/E₂ and P/F ratios that were discriminative for achieving or not achieving clinical pregnancy were 0.36 and 0.17, respectively. The clinical pregnancy rates were found to be significantly different between below and above P/E₂ cutoff values (49.8% vs. 40.1%, respectively, p = .031), while there were no significant differences between below and above P/F cutoff values regarding the pregnancy outcomes.

CONCLUSION

The P/E₂ and P/F ratios were found to be more efficient and reliable markers than serum progesterone level alone in predicting the reproductive outcomes of assisted reproduction cycles without a premature rise in serum progesterone levels. A P/E₂ ratio ≤0.36 and a P/F ratio ≤0.17 significantly improved the cycle outcomes.

The effect of late-follicular phase progesterone elevation on embryo ploidy and cumulative live birth rates

RESEARCH QUESTION

Does late-follicular phase progesterone elevation have a deleterious effect on embryo euploidy, blastocyst formation rate and cumulative live birth rates (CLBR)?

DESIGN

A multicentre retrospective cross-sectional study including infertile patients aged 18-40 years who underwent ovarian stimulation in a gonadotrophin-releasing hormone antagonist protocol and preimplantation genetic testing for aneuploidies (PGT-A) followed by a freeze-all strategy and euploid embryo transfer between August 2017 and December 2019. The sample was stratified according to the progesterone concentrations on the day of trigger: normal (≤1.50 ng/ml) and high (>1.50 ng/ml). Moreover, sensitivity analyses were performed to determine whether different conclusions would have been drawn if different cut-offs had been adopted. The primary outcome was the embryo euploidy rate. Secondary outcomes were the blastocyst formation rate, the number of euploid blastocysts and CLBR.

RESULTS

Overall 1495 intracytoplasmic sperm injection PGT-A cycles were analysed. Late-follicular phase progesterone elevation was associated with significantly higher late-follicular oestradiol concentrations (2847.56 ± 1091.10 versus 2240.94 ± 996.37 pg/ml, P < 0.001) and significantly more oocytes retrieved (17.67 ± 8.86 versus 12.70 ± 7.00, P < 0.001). The number of euploid embryos was significantly higher in the progesterone elevation group (2.32 ± 1.74 versus 1.86 ± 1.42, P = 0.001), whereas the blastocyst formation rate (47.1% [43.7-50.5%] versus 51.0% [49.7-52.4%]), the embryo euploidy rate (48.3% [44.9-51.7%] versus 49.1% [47.7-50.6%], the live birth rate in the first frozen embryo transfer (34.1% versus 31.1%, P = 0.427) and CLBR (38.9% versus 37.0%, P = 0.637) were not significantly different between the two groups.

CONCLUSIONS

Euploidy rate and CLBR do not significantly differ among PGT-A cycles with and without late-follicular progesterone elevation in a freeze-all approach.

Is a freeze-all policy the optimal solution to circumvent the effect of late follicular elevated progesterone? A multicentric matched-control retrospective study analysing cumulative live birth rate in 942 non-elective freeze-all cycles

STUDY QUESTION

Is late follicular elevated progesterone (LFEP) in the fresh cycle hindering cumulative live birth rates (CLBRs) when a freeze only strategy is applied?

SUMMARY ANSWER

LFEP in the fresh cycle does not affect the CLBR of the frozen transfers in a freeze only approach, nor the embryo freezing rate.

WHAT IS KNOWN ALREADY

Ovarian stimulation promotes the production of progesterone (P) which has been demonstrated to have a deleterious effect on IVF outcomes. While there is robust evidence that this elevation produces impaired endometrial receptivity, the impact on embryo quality remains a matter of debate. In particular, previous studies have shown that LFEP is associated with a hindered CLBR. However, most clinical insight on the effect of progesterone on embryo quality in terms of CLBRs have focused on embryo transfers performed after the fresh transfer, thus excluding the first embryo of the cohort. To be really informative on the possible detrimental effects of LFEP, evidence should be derived from freeze-all cycles where no fresh embryo transfer is performed in the presence of progesterone elevation, and the entire cohort of embryos is cryopreserved.

STUDY DESIGN, SIZE, DURATION

This was a matched case-control, multicentre (three centres), retrospective analysis including all GnRH antagonist ICSI cycles in which a freeze all (FA) policy of embryos on day 3/5/6 of embryonic development was applied between 2012 and 2018. A total of 942 patients (471 cases with elevated P and 471 matched controls with normal P values) were included in the analysis. Each patient was included only once.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The sample was divided according to the following P levels on the day of ovulation triggering: <1.50 ng/ml and ≥1.50 ng/ml. The matching of the controls was performed according to age (±1 year) and number of oocytes retrieved (±10%). The main outcome was CLBR defined as a live-born delivery after 24 weeks of gestation.

MAIN RESULTS AND THE ROLE OF CHANCE

The baseline characteristics of the two groups were similar. Estradiol levels on the day of trigger were significantly higher in the elevated P group. There was no significant difference in terms of fertilisation rate between the two groups. The elevated P group had significantly more cleavage stage frozen embryos compared to the normal P group while the total number of cryopreserved blastocyst stage embryos was the same. The CLBR did not differ between the two study groups (29.3% and 28.2% in the normal versus LFEP respectively, P = 0.773), also following confounder adjustment using multivariable GEE regression analysis (accounting for age at oocyte retrieval, total dose of FSH, progesterone levels on the day of ovulation trigger, day of freezing, at least one top-quality embryo transferred and number of previous IVF cycles, as the independent variables).

LIMITATIONS, REASONS FOR CAUTION

This is a multicentre observational study based on a retrospective data analysis. Better extrapolation of the results could be validated by performing a prospective analysis.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study demonstrating that LFEP in the fresh cycle does not hinder CLBR of the subsequent frozen cycles in a FA approach. Thus, a FA strategy circumvents the issue of elevated P in the late follicular phase.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for this study. Throughout the study period and manuscript preparation, authors were supported by departmental funds from: Centre for Reproductive Medicine, Brussels, Belgium; Infertility Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy; Centro Scienze Natalità, San Raffaele Scientific Institute, Milan, Italy; and IVI-RMA, Lisbon, Portugal. E.S. has competing interests with Ferring, Merck-Serono, Theramex and Gedeon-Richter outside the submitted work. E.P. reports grants from Ferring, grants and personal fees from Merck-Serono, grants and personal fees from MSD and grants from IBSA outside the submitted work. All the other authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Effects of immediate versus delayed frozen embryo transfer in high responder patients undergoing freeze-all cycles

Background

Frozen embryo transfer (FET) can greatly improve the pregnancy outcomes for high responder patients. However, it is not known whether the timing of FET is a risk factor on pregnancy outcomes in high responder patients undergoing freeze-all cycles.

Methods

A retrospective cohort study to compare the pregnancy outcomes of the immediate and delayed FET groups in high responder patients undergoing freeze-all cycles. The two groups were defined as that FET took place either within the first menstrual cycle following oocyte retrieval or afterwards. Propensity score matching was used to make the potential risk factors of the two groups comparable. Multivariable regression analysis was used to study the effect of the timing of FET on pregnancy outcomes in the entire cohort and propensity score-matched cohort, even in different controlled ovarian hyperstimulation protocol cohorts as subgroup analysis.

Results

We obtained 1130 patients in immediate FET group and 998 patients in delayed FET group, and the average age of the two groups were 30.30 and 30.63. We showed that the immediate FET group were equivalent to delayed FET group in the entire cohort [clinical pregnancy rate (CPR), 61.0% versus 63.4%, adjusted odd ratio (OR), 0.939, 95% confidence interval (CI), 0.781–1.129; spontaneous abortion rate (SAR), 10.1% versus 12.6%, adjusted OR, 0.831, 95% Cl (0.628–1.098); live birth rate (LBR), 49.9% versus 49.2%, adjusted OR, 1.056, 95% Cl (0.883–1.263)]. The same results were obtained by χ² test in the propensity score-matched cohort (CPR, 60.5% versus 63.5%; SAR, 11.6% versus 12.3%; LBR, 48% versus 49.3%) (P > 0.05). Subgroup analysis indicated that pregnancy outcomes of immediate FET were no difference to delayed FET in gonadotropin-releasing hormone agonist (GnRH-a) protocol (P > 0.05). The SAR of the immediate FET group were lower than that of the delayed FET group in GnRH antagonist protocol (adjusted OR, 0.645, 95% CI, 0.430–0.966) (P < 0.05), no differences were observed in CPR and LBR (P > 0.05).

Conclusions

The pregnancy outcomes of immediate FET were no difference to delayed FET in high responder population undergoing freeze-all cycles.

Progesterone/Oestradiol ratio can Better Predict Intracytoplasmic Sperm Injection Outcomes than Absolute Progesterone Level

Background:

Several parameters were proposed to predict the impact of premature luteinization on intracytoplasmic sperm injection (ICSI) outcomes such as isolated progesterone (P) level, progesterone to oocyte ratio, and progesterone/estradiol ratio (P/E2).

Aim:

The aim of this study is to compare the predictive value of P/E2 ratio and isolated P level on the ovulation triggering day for pregnancy outcomes in fresh GnRH antagonist ICSI cycles.

Settings and Design:

A retrospective cohort study conducted in a university-affiliated in vitro fertilization center between January 2017 and April 2019.

Methods:

The study included women who underwent their first- or second-ranked GnRH antagonist ICSI cycles with day-3 embryo transfer. P/E2 ratio was calculated as (P [ng/mL] × 1000)/E2 (pg/mL). Cutoff values of ≥1.5 ng/ml for high P (HP) and ≥0.55 for HP/E2 ratio were chosen based on the literature.

Statistical Analysis:

A receiver operating curve was performed to detect the predictability of serum P/E2 and P for the ongoing pregnancy rate. First, patients were divided according to either P level (low P < 1.5 ng/mL and HP ≥1.5 ng/mL) or P/E2 ratio (low P/E2 <0.55 and HP/E2 ≥ 0.55). Patients were further divided into four subgroups: (Group A: HP and HP/E2 ratio, Group B: low P and low P/E2 ratio, Group C: HP only, and Group D: HP/E2 only). A multivariate regression analysis models were used to account for the effect of the cycle confounders on the likelihood of pregnancy.

Results:

A total of 402 ICSI cycles were analyzed. The area under the curve was 0.67 and 0.59 for P/E2 and P, respectively. P/E2 showed a significant association with ongoing pregnancy (adjusted odds ratios [aOR]: 0.409, 95% confidence interval [CI] 0.222–0.753, P = 0.004) while HP revealed no significant predictive value (aOR: 0.542, 95% CI 0.284–1.036, P = 0.064) after the multivariate analysis.

Conclusions:

P elevation may not present as an independent predictor for cycle outcomes. P/E2 ratio has a better prognostic value than P alone in predicting pregnancy of GnRH antagonist cycles.

Progesterone levels on the human chorionic gonadotropin trigger day affect the pregnancy rates for embryos transferred at different stages of development in both general and selected IVF/ICSI populations

Background

Two meta-analyses have shown that pregnancy and birth rates are significantly higher after blastocyst transfer than after cleaved embryo transfer. Other studies have revealed that a serum progesterone level > 1.5 ng/ml on the trigger day is responsible for premature luteinization and is associated with a low pregnancy rate. The objectives of this retrospective study were to determine whether blastocyst transfer gave higher pregnancy rates than cleaved embryo transfer at day 3 in both the general and selected IVF/ICSI populations, and whether the serum progesterone level influenced the pregnancy rate.

Method

We studied IVF/ICSI cycles with GnRH antagonist - FSH/hMG protocols in a general population (n = 1210) and a selected “top cycle” population (n = 677), after blastocyst transfer on day 5 or cleaved embryo transfer on day 3. The selected couples had to meet the following criteria: female age < 35, first or second cycle, and one or two embryos transferred. We recorded predictive factors for pregnancy and calculated the progesterone to oocyte index (POI), the progesterone:estradiol ratio (P:E2 ratio), and the progesterone to follicle (> 14 mm) index (PFI).

Results

In the general population, the clinical pregnancy rate was significantly higher after blastocyst transfer (33.3%) than after cleaved embryo transfer (25.3%; p <  0.01); the same was true for the birth rate (32.1 and 22.8%, respectively, p <  0.01). The differences between blastocyst and embryo transfer groups were not significant in the selected population (respectively 35.7% vs. 35.8% for the clinical pregnancy rate, and 33.9 and 34.9% for the birth rate). The serum progesterone levels on the eve of the trigger day and on the day itself were significantly lower in the pregnant women (p <  0.01). We found a serum progesterone threshold of 0.9 ng/ml, as also reported by other researchers. The POI and the PFI appear to have predictive value for cleaved embryos transfers.

Conclusions

Blastocyst transfers were associated with higher clinical pregnancy and birth rates than cleaved embryo transfers in a general population but not in a selected population. The serum progesterone levels on the eve of the trigger day and on the day itself predicted the likelihood of pregnancy.

Late follicular phase progesterone elevation during ovarian stimulation is not associated with decreased implantation of chromosomally screened embryos in thaw cycles

STUDY QUESTION

What is the impact of a late follicular phase progesterone elevation (LFPE) during controlled ovarian hyperstimulation (COH) on embryonic competence and reproductive potential in thaw cycles of preimplantation genetic testing for aneuploidy (PGT-A) screened embryos?

SUMMARY ANSWER

Our study findings suggest that LFPE, utilizing a progesterone cutoff value of 2.0 ng/ml, is neither associated with impaired embryonic development, increased rate of embryonic aneuploidy, nor compromised implantation and pregnancy outcomes following a euploid frozen embryo transfer (FET) cycle.

WHAT IS KNOWN ALREADY

Premature progesterone elevation during COH has been associated with lower pregnancy rates due to altered endometrial receptivity in fresh IVF cycles. Also, increased levels of progesterone (P) have been suggested to be a marker for ovarian dysfunction, with some evidence to show an association between LFPE and suboptimal embryonic development. However, the effect of LFPE on embryonic competence is still controversial.

STUDY DESIGN, SIZE, DURATION

Retrospective cohort analysis in a single, academic ART center from September 2016 to March 2020. In total, 5244 COH cycles for IVF/PGT-A were analyzed, of those 5141 were included in the analysis. A total of 23 991 blastocysts underwent trophectoderm biopsy and PGT analysis. Additionally, the clinical IVF outcomes of 5806 single euploid FET cycles were evaluated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Cohorts were separated in two groups: Group 1: oocytes retrieved from cycles with normal P levels during ovulation trigger (P ≤ 2.0 ng/ml); Group 2: oocytes retrieved after cycles in which LFPE was noted (P > 2.0 ng/ml). Extended culture and PGT-A was performed. Secondly, IVF outcomes after a single euploid FET were evaluated for each cohort.

MAIN RESULTS AND THE ROLE OF CHANCE

Four thousand nine hundred and twenty-five cycles in Group 1 were compared with 216 cycles on Group 2. Oocyte maturity rates, fertilization rates and blastulation rates were comparable among groups. A 65.3% (n = 22 654) rate of utilizable blastocysts was found in patients with normal P levels and were comparable to the 62.4% (n = 1337) observed in those with LFPE (P = 0.19). The euploidy rates were 52.8% (n = 11 964) and 53.4% (n = 714), respectively, albeit this difference was not statistically significant (P = 0.81). Our multivariate analysis was fitted with a generalized estimating equation (GEE) and no association was found with LFPE and an increased odds of embryo aneuploidy (adjusted odds ratio 1.04 95% CI 0.86-1.27, P = 0.62). A sub-analysis of subsequent 5806 euploid FET cycles (normal P: n = 5617 cycles and elevated P: n = 189 cycles) showed no differences among groups in patient's BMI, Anti-Müllerian hormone (AMH), endometrial thickness at FET and number of prior IVF cycles. However, a significant difference was found in patient's age and oocyte age. The number of good quality embryos transferred, implantation rate, clinical pregnancy rate, ongoing pregnancy rate, multiple pregnancy rate and clinical pregnancy loss rates were comparable among groups. Of the registered live births (normal P group: n = 2198; elevated P group: n = 52), there were no significant differences in gestational age weeks (39.0 ± 1.89 versus 39.24 ± 1.53, P = 0.25) and birth weight (3317 ± 571.9 versus 3 266 ± 455.8 g, P = 0.26) at delivery, respectively.

LIMITATIONS, REASONS FOR CAUTION

The retrospective nature of the study and probable variability in the study center's laboratory protocol(s), selected progesterone cutoff value and progesterone assay techniques compared to other ART centers may limit the external validity of our findings.

WIDER IMPLICATIONS OF THE FINDINGS

Based on robust sequencing data from a large cohort of embryos, we conclude that premature P elevation during IVF stimulation does not predict embryonic competence. Our study results show that LFPE is neither associated with impaired embryonic development nor increased rates of aneuploidy. Embryos obtained from cycles with LFPE can be selected for transfer, and patients can be reassured that the odds of achieving a healthy pregnancy are similar to the embryos exposed during COH cycles to physiologically normal P levels.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for the realization of this study. Dr A.B.C. is advisor and/or board member of Sema 4 (Stakeholder in data), Progyny and Celmatix. The other authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NA.

Varying levels of serum estradiol do not alter the timing of the early endometrial secretory transformation

STUDY QUESTION

Do supraphysiologic estradiol (E2) levels in the ranges attained during normal and high response superovulation cycles modify the onset of endometrial secretory transformation?

SUMMARY ANSWER

Highly supraphysiologic levels of E2 do not alter the ability of physiologic levels of progesterone (P4) to induce secretory transformation.

WHAT IS KNOWN ALREADY

Previous studies have demonstrated that premature P4 elevations during IVF cycles are associated with a decrement in clinical pregnancy rates after fresh embryo transfer due to shifts in the window of implantation (WOI). However, alterations in the onset of secretory transformation may not apply uniformly to all patients. High responders with supraphysiologic E2 levels accompanied by similar subtle increases in P4 have not been shown to have decreased sustained implantation rates. This prospective investigation in which whole-genome transcriptomic and methylomic analysis of the endometrium is performed for individual patients under a range of E2 concentrations brings clarity to a long-debated issue.

STUDY DESIGN, SIZE, DURATION

A randomized, prospective and paired trial was conducted in which 10 participants were enrolled and randomized to the order in which they completed three distinct uterine stimulation cycles, each at a specific E2 concentration: physiologic (∼180 pg/ml), moderately supraphysiologic (600-800 pg/ml) or supraphysiologic (2000 pg/ml). Target E2 ranges were selected to mimic those seen in natural, controlled ovarian stimulation and IVF cycles. E2 valerate was administered in order to maintain stable E2 levels for 12 days followed by intramuscular P4 in oil 10 mg/day for two doses, after which an endometrial biopsy was performed. A total of 30 endometrial biopsies were included in a whole-genome transcriptomic and methylomic analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Healthy volunteers without a history of infertility were included in this study at a single large infertility center. DNA was isolated from the endometrial biopsy specimens and bisulfite sequencing was performed to construct a methylation array. Differential methylation analysis was conducted based on differences in M-values of individuals across treatment groups for each probe as well as carrying out t-tests. RNA was isolated for RNA-Seq analysis and gene expression values were compared using DESeq2. All analyses were performed in a pairwise fashion to compare among the three stimulation cycles within individuals and secondarily to compare all participants in each of the cycles.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean peak E2 and P4 levels were 275 pg/ml and 4.17 ng/ml in the physiologic group, 910 pg/ml and 2.69 ng/ml in the moderate group was, and 2043 pg/ml and 2.64 ng/ml in the supraphysiologic group, respectively. Principal component analysis of 834 913 CpG sites was performed on M-values of individuals within the low, moderate and supraphysiologic conditions in a paired approach. There were no differences in genome-wide methylation within participants across E2 groups. A paired analysis revealed that gene expression profiles did not differ within the same individual at each of the three E2 levels. No significant alterations in gene expression as related to endometrial physiology were identified between the low, moderate and supraphysiologic groups in an inter-participant analysis.

LIMITATIONS, REASONS FOR CAUTION

Although each participant completed a physiologic cycle in which E2 levels were maintained in a range that would simulate a natural cycle, our findings are limited by lack of an unmedicated control to assess if there was a potential effect from E2V. Additionally, our results were obtained in fertile individuals, who may have a different endometrial response compared to an infertile population. Despite the whole genomic endometrial assessment and rigorous, paired study design, the sample size was limited.

WIDER IMPLICATIONS OF THE FINDINGS

Given that the endometrial response to P4 is unaffected by E2 levels in the supraphysiologic range, diminutions in implantation seen in stimulated cycles may result from embryonic-endometrial dyssynchrony following early P4 elevations or slowly blastulating embryos, which occur independently of the magnitude of the E2 rise.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Foundation for Embryonic Competence, Basking Ridge, NJ, USA. Dr E.S. reports consultancy work for The Foundation for Embryonic Competence, Basking Ridge, NJ, USA. The other authors declare no conflict of interests related to this topic.

TRIAL REGISTRATION NUMBER

NCT02458404.

Elevation of progesterone on the trigger day exerts no carryover effect on live birth in freeze-all cycles

AIM

To evaluate the effect of trigger day progesterone (P) levels on live birth in freeze-all cycles.

MATERIAL AND METHODS

Retrospective analysis of 1034 freeze-all female patients aged <38 years with single blastocyst transfers. Patients with (n = 268) or without (n = 766) preimplantation genetic test for aneuploidy (PGT-A) arm were further categorized into three subgroups based on trigger day P levels; low (<0.80 ng/ml), medium (0.8-1.49 ng/ml), and high (≥1.50 ng/ml).

RESULTS

Estradiol (E2) levels on trigger day, the number of oocytes retrieved and the number of mature oocytes increased significantly with increasing serum p values in cycles without and with PGT-A arms. Significant correlation was found between E2 levels on trigger day and serum P levels and between the number of total oocytes retrieved and serum P levels Live birth rates were similar in the three subgroups in without PGT-A arm (51%, 52.6%, and 51.5%, respectively; p = .922) and with PGT-A arm (55.1%, 55.1%, and 62.5%, respectively; p = .730). Multivariate regression analysis revealed that trigger day P levels were not significant for live birth.

CONCLUSION

The proposal that trigger day progesterone elevation (PE) exerts a detrimental effect on oocyte and embryo competence has no clinical validity.

hCG day progesterone level has no impact on the frozen thawed embryo transfer cycle outcome

OBJECTIVE

To assess the association between hCG day progesterone levels and subsequent frozen-thawed embryo transfer (FET) cycle outcome in infertile women with and without polycystic ovary syndrome (PCOS).

METHOD

Data of 178 women who underwent FET at a university-based infertility clinic between January 2016 and December 2019 were reviewed. The study group consisted of women who had progesterone elevation (PE) during fresh controlled ovarian stimulation (COS) cycle. A sub-group analysis was also performed in PCOS and non-PCOS patients.

RESULTS

There were no differences in clinical pregnancy (47.7 % vs. 50.7 %, p = 0.729), miscarriage (15.9 % vs. 22.4 %, p = 0.359), and live birth rates (27.3 % vs. 23.9 %, p = 0.652) following FET between women with and without PE in the fresh cycle. The results remained non-significant regarding the clinical pregnancy (46.7 % vs. 53.4 %, p = 0.549), miscarriage (13.3 % vs. 27.6 %, p = 0.133), and live birth rates (26.7 % vs. 19.0 %, p = 0.408) in participants with PCOS (n = 88).

CONCLUSION

hCG day progesterone level in the fresh COS cycle does not have a significant impact on the subsequent FET cycle neither in PCOS nor in non-PCOS women.

Elevated serum progesterone during in vitro fertilization treatment and the risk of ischemic placental disease

BACKGROUND

Elevated progesterone on the day of human chorionic gonadotropin (hCG) administration is associated with decreased live birth rates in IVF cycles. The association with adverse pregnancy outcomes is unknown.

OBJECTIVES

Assess the association between serum progesterone on the day of hCG administration and the risk of ischemic placental disease [IPD; preeclampsia, placental abruption, and/or small for gestational age (SGA)].

METHODS

We conducted a retrospective cohort study of autologous fresh IVF cycles resulting in delivery between 2005 and 2018. All IVF procedures were conducted at a large, university-affiliated infertility center. Patients were divided into tertiles based on their serum progesterone level on the day of hCG administration; the lowest tertile served as the reference group. We identified pregnancies complicated by preeclampsia and placental abruption using ICD-9/10 codes and medical record review. We defined SGA as < 10th percentile using U.S. growth curves.

RESULTS

The cohort included 166 deliveries in the lowest tertile of progesterone (0.2-0.73 ng/ml), 166 deliveries in the middle (0.64-1.05 ng/ml) and 167 deliveries in the highest tertile (1.05-5.6 ng/ml). Compared with the lowest tertile, the risk of IPD was greater in the middle (RR 1.6; 95% CI 1.1-2.5) tertile after adjustment for age, parity, number of oocytes retrieved, and estradiol. The highest tertile was also not associated with an increased risk of IPD.

CONCLUSION

In an IVF population, elevated serum progesterone in the range of 0.64-1.05 ng/mL on the day of hCG administration was associated with a small increased risk of IPD.

Time from oocyte retrieval to frozen embryo transfer in the natural cycle does not impact reproductive or neonatal outcomes

OBJECTIVE

To determine if the time from oocyte retrieval to frozen embryo transfer (FET) in the natural cycle affects reproductive or neonatal outcomes.

DESIGN

Retrospective cohort.

SETTING

Not applicable.

PATIENT(S)

Five hundred and seventy-six consecutive freeze-all cycles from January 2011 to December 2018 followed by natural cycle FET of a single blastocyst.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Primary outcome of live birth; secondary outcomes of preterm delivery (24-37 weeks) and small for gestational age (SGA) with a multivariable logistic regression performed with adjustment for age, infertility diagnosis, ovulatory trigger type, and preimplantation genetic testing (PGT).

RESULT(S)

Before adjustment for confounding, we found a statistically significantly different live-birth rate (57.7% vs. 48.6%) for natural cycle FET occurring in the first versus second menstrual cycle, respectively. In a multivariate analysis, performing a natural cycle FET of a single blastocyst in the second compared with the first menstrual cycle did not statistically significantly impact the odds of live-birth rate. After adjustment for age, diagnosis, and ovulatory trigger type, only PGT was associated with statistically significantly increased odds of live birth compared with no PGT. There were no differences in the incidence of SGA (male, 6.6% vs. 2.3%; female, 9.8% vs. 11.1%) or preterm delivery (1.6% vs. 5.6%) between both groups.

CONCLUSION(S)

Performing a natural cycle FET of a single blastocyst in the second compared with the first menstrual cycle after ovarian stimulation did not statistically significantly impact the odds of live birth or neonatal outcomes.

The impact of preovulatory versus midluteal serum progesterone level on live birth rates during fresh embryo transfer

BACKGROUND

Conflicting evidence still prevails concerning the effect of preovulatory elevated progesterone (EP4) on reproductive outcomes in fresh embryo transfer (ET). However, few studies have analyzed the effect of EP4 on the likelihood of pregnancy using multivariate regression approach. The potential confounding factors tested in these studies were limited to either patient's characteristics or to stimulation related parameters. Yet, several studies have shown that postovulatory parameters such as midluteal progesterone (P4) level may be considered as a proxy variable of endometrial receptivity as well.

OBJECTIVE

The aim of the present study was to estimate the independent effect of preovulatory P4 effect, if any, on the probability of live birth (LB) by considering the midluteal endocrine profile when controlling for the potential confounding factors.

METHODS

This is a secondary data analysis of a cohort of fresh IVF/ICSI cycles triggered with GnRH agonist (n = 328) performed in a single IVF center during the period 2014-2016. Patients contributed only one cycle and were stratified into four groups according to preovulatory P4 quartiles. We assessed the association between preovulatory P4 and the odds of LB calculated by logistic regression analysis after controlling for the most clinically relevant confounders. The primary outcome measure: Live birth rates (LBR).

RESULTS

Both preovulatory and midluteal P4 were significantly correlated with the ovarian response. Logistic regression analysis showed that preovulatory serum P4 did not have a significant impact on LBR. In contrast, midluteal serum P4 level was an important independent factor associated with LBR. The optimal chance of LBR was achieved with midluteal serum P4 levels of 41-60 ng/ml, [OR: 2.73 (1.29-5.78); p< 0.008].

CONCLUSION

The multivariate analysis suggests that the midluteal P4 level seems to impact LBR more than the preovulatory P4 level in women undergoing IVF treatment followed by fresh ET.

Fresh versus frozen embryo transfers in assisted reproduction

BACKGROUND

In vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) treatments conventionally consist of a fresh embryo transfer, possibly followed by one or more cryopreserved embryo transfers in subsequent cycles. An alternative option is to freeze all suitable embryos and transfer cryopreserved embryos in subsequent cycles only, which is known as the 'freeze all' strategy. This is the first update of the Cochrane Review on this comparison.

OBJECTIVES

To evaluate the effectiveness and safety of the freeze all strategy compared to the conventional IVF/ICSI strategy in women undergoing assisted reproductive technology.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two registers of ongoing trials from inception until 23 September 2020 for relevant studies, checked references of publications found, and contacted study authors to obtain additional data.

SELECTION CRITERIA

Two review authors (TZ and MZ) independently selected studies for inclusion, assessed risk of bias, and extracted study data. We included randomised controlled trials comparing a 'freeze all' strategy with a conventional IVF/ICSI strategy including a fresh embryo transfer in women undergoing IVF or ICSI treatment.

DATA COLLECTION AND ANALYSIS

The primary outcomes were cumulative live birth rate and ovarian hyperstimulation syndrome (OHSS). Secondary outcomes included effectiveness outcomes (including ongoing pregnancy rate and clinical pregnancy rate), time to pregnancy and obstetric, perinatal and neonatal outcomes.

MAIN RESULTS

We included 15 studies in the systematic review and eight studies with a total of 4712 women in the meta-analysis. The overall evidence was of moderate to low quality. We graded all the outcomes and downgraded due to serious risk of bias, serious imprecision and serious unexplained heterogeneity. Risk of bias was associated with unclear blinding of investigators for preliminary outcomes of the study during the interim analysis, unit of analysis error, and absence of adequate study termination rules. There was an absence of high-quality evidence according to GRADE assessments for our primary outcomes, which is reflected in the cautious language below. There is probably little or no difference in cumulative live birth rate between the 'freeze all' strategy and the conventional IVF/ICSI strategy (odds ratio (OR) 1.08, 95% CI 0.95 to 1.22; I² = 0%; 8 RCTs, 4712 women; moderate-quality evidence). This suggests that for a cumulative live birth rate of 58% following the conventional strategy, the cumulative live birth rate following the 'freeze all' strategy would be between 57% and 63%. Women might develop less OHSS after the 'freeze all' strategy compared to the conventional IVF/ICSI strategy (OR 0.26, 95% CI 0.17 to 0.39; I² = 0%; 6 RCTs, 4478 women; low-quality evidence). These data suggest that for an OHSS rate of 3% following the conventional strategy, the rate following the 'freeze all' strategy would be 1%. There is probably little or no difference between the two strategies in the cumulative ongoing pregnancy rate (OR 0.95, 95% CI 0.75 to 1.19; I² = 31%; 4 RCTs, 1245 women; moderate-quality evidence).  We could not analyse time to pregnancy; by design, time to pregnancy is shorter in the conventional strategy than in the 'freeze all' strategy when the cumulative live birth rate is comparable, as embryo transfer is delayed in a 'freeze all' strategy. We are uncertain whether the two strategies differ in cumulative miscarriage rate because the evidence is very low quality (Peto OR 1.06, 95% CI 0.72 to 1.55; I² = 55%; 2 RCTs, 986 women; very low-quality evidence) and cumulative multiple-pregnancy rate (Peto OR 0.88, 95% CI 0.61 to 1.25; I² = 63%; 2 RCTs, 986 women; very low-quality evidence). The risk of hypertensive disorders of pregnancy (Peto OR 2.15, 95% CI 1.42 to 3.25; I² = 29%; 3 RCTs, 3940 women; low-quality evidence), having a large-for-gestational-age baby (Peto OR 1.96, 95% CI 1.51 to 2.55; I² = 0%; 3 RCTs, 3940 women; low-quality evidence) and a higher birth weight of the children born (mean difference (MD) 127 g, 95% CI 77.1 to 177.8; I² = 0%; 5 RCTs, 1607 singletons; moderate-quality evidence) may be increased following the 'freeze all' strategy. We are uncertain whether the two strategies differ in the risk of having a small-for-gestational-age baby because the evidence is low quality (Peto OR 0.82, 95% CI 0.65 to 1.05; I² = 64%; 3 RCTs, 3940 women; low-quality evidence).

AUTHORS' CONCLUSIONS

We found moderate-quality evidence showing that one strategy is probably not superior to the other in terms of cumulative live birth rate and ongoing pregnancy rate. The risk of OHSS may be decreased in the 'freeze all' strategy. Based on the results of the included studies, we could not analyse time to pregnancy. It is likely to be shorter using a conventional IVF/ICSI strategy with fresh embryo transfer in the case of similar cumulative live birth rate, as embryo transfer is delayed in a 'freeze all' strategy. The risk of maternal hypertensive disorders of pregnancy, of having a large-for-gestational-age baby and a higher birth weight of the children born may be increased following the 'freeze all' strategy. We are uncertain if 'freeze all' strategy reduces the risk of miscarriage, multiple pregnancy rate or having a small-for-gestational-age baby compared to conventional IVF/ICSI.

Pre-ovulatory hormones on day of human chorionic gonadotropin trigger and assisted reproductive technique outcomes in different ovarian response groups

Background:

Aims:

Setting and Design:

Materials and Methods:

Statistical Analysis:

Results:

Conclusion:

Female age is associated with the optimal number of oocytes to maximize fresh live birth rates: an analysis of 256,643 fresh ART cycles

RESEARCH QUESTION

What is the optimal number of oocytes retrieved at which maximum live birth rate is observed after fresh autologous assisted reproductive technology (ART) cycles for women of different ages?

DESIGN

Retrospective cohort study of all fresh autologous ART aspiration cycles (n = 256,643) undertaken in Australia and New Zealand between 2009 and 2015. Primary outcome measure was live birth rate (LBR) (delivery of at least one liveborn baby at 20 weeks' gestation or over per fresh aspiration cycle). Cycles were grouped according to female age (<30, 30-34, 35-49, 40-44 and ≥45 years) and ovarian response (one to three, four to nine, 10-14, 15-19, 20-25 and ≥25 oocytes). Secondary outcome was incidence of ovarian hyperstimulation syndrome (OHSS) requiring hospitalization.

RESULTS

At different oocyte yields, LBR per fresh aspiration cycle peaked and then declined at, depending on female age: <30 years: six to 11 oocytes (LBR 31-34%); 30-34 years: 11-16 oocytes (LBR 29-30%); 35-39 years: nine to 17 oocytes (LBR 21-24%); and 40-44 years: 15-17 oocytes (LBR 11-12%). The incidence of OHSS increased significantly with the number of oocytes retrieved, from 1.2% with 15 oocytes retrieved to 9.3% with 30 or more oocytes retrieved (P < 0.001).

CONCLUSION

The optimal number of oocytes at which maximum LBR was observed in a fresh aspiration cycle was highly dependent on age. Because of the observational nature of the results, a cause-effect relationship between the number of oocytes retrieved and LBR should not be assumed; evidence from well-designed randomized control trials is required before clinical advice can be suggested.

The relationship between a novel evaluation parameter of premature luteinization and IVF outcomes

RESEARCH QUESTION

Can premature luteinization of granulosa cells (PLGC) act as a novel parameter of premature luteinization and affect IVF outcomes?

STUDY DESIGN

In this retrospective cohort study, infertile patients undergoing fresh IVF cycles between January 2006 and December 2016 at the Reproductive Medicine Center in Tongji Hospital were included. A total of 42,468 cycles were conducted. Propensity score matching was carried out to match the baseline characteristics, and participants were assigned to the PLGC group and control group. The main outcomes were pregnancy rate and live birth rate.

RESULTS

Patient characteristics and clinical outcomes were compared before and after matching. In general, the fate of oocytes in the PLGC group was much worse than those in the control group after matching, including metaphase II rate, two-pronuclei rate, available embryo rate, blastocyst formation rate, high-quality blastocyst rate, pregnancy rate, implantation rate and live birth rate. Among those potential risk factors, gonadotrophin duration, oestradiol and progesterone on HCG day were positively associated with the occurrence of PLGC in the multivariate logistic regression model, with gonadotrophin dosage negatively related. Moreover, cumulus-oocyte complexes with PLGC showed a high correlation with elevated progesterone levels over 1.5 ng/ml.

CONCLUSIONS

Our findings demonstrated the adverse effect of PLGC on oocyte competency. In evaluating cumulus-oocyte complexes, PLGC provide an available novel parameter for premature luteinization judgement in clinical and individualized precise treatment. Close monitoring of progesterone level as well as critical analysis of progesterone elevation can reduce the occurrence of premature luteinization.

The Association Between Elevated Progesterone Level on Day of hCG Trigger and Live Birth Rates in ART Cycles: A Single Centre Observational Study

BACKGROUND

The advent of ovarian stimulation within an in vitro fertilization (IVF) cycle has resulted in modifying the physiology of stimulated cycles and has helped optimize pregnancy outcomes. In this regard, the importance of progesterone (P4) elevation at time of human chorionic gonadotrophin (hCG) administration within an IVF cycle has been studied over several decades. Our study aimed to evaluate the association of P4 levels at time of hCG trigger with live birth rate (LBR), clinical pregnancy rate (CPR) and miscarriage rate (MR) in fresh IVF or IVF-ICSI cycles.

METHODS

This was a retrospective cohort study (n=170) involving patients attending the Centre for Reproductive and Genetic Health (CRGH) in London. The study cohort consisted of women undergoing controlled ovarian stimulation using GnRH antagonist or GnRH agonist protocols. Univariate and multiple logistic regression analyses were used to evaluate the association of clinical outcomes. Differences were considered statistically significant if p≤0.05.

RESULTS

As serum progesterone increased, a decrease in LBR was observed. Following multivariate logistical analyses, LBR significantly decreased with P4 thresholds of 4.0 ng/ml (OR 0.42, 95% CI:0.17-1.0) and 4.5 ng/ml (OR 0.35, 95% CI:0.12-0.96).

CONCLUSION

P4 levels are important in specific groups and the findings were statistically significant with a P4 threshold value between 4.0-4.5 ng/ml. Therefore, it seems logical to selectively measure serum P4 levels for patients who have ovarian dysfunction or an ovulatory cycles and accordingly prepare the individualized management packages for such patients.

Progestins for pituitary suppression during ovarian stimulation for ART: a comprehensive and systematic review including meta-analyses

BACKGROUND

Progestins are capable of suppressing endogenous LH secretion from the pituitary. Progestins can be used orally and are less expensive than GnRH analogues. However, early endometrial exposure to progestin precludes a fresh embryo transfer (ET), but the advent of vitrification and increasing number of oocyte cryopreservation cycles allow more opportunities for using progestins for pituitary suppression.

OBJECTIVE AND RATIONALE

This review summarizes: the mechanism of pituitary suppression by progestins; the effectiveness of progestins when compared with GnRH analogues and with each other; the effect of progestins on oocyte and embryo developmental potential and euploidy status; and the cost-effectiveness aspects of progestin primed stimulation. Future research priorities are also identified.

SEARCH METHODS

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed, the Web of Science and Scopus were screened with a combination of keywords related to ART, progesterone, GnRH analogue and ovarian stimulation, in various combinations. The search period was from the date of inception of each database until 1 April 2020. Only full text papers published in English were included.

OUTCOMES

Overall, the duration of stimulation, gonadotrophin consumption and oocyte yield were similar with progestins and GnRH analogues. However, sensitivity analyses suggested that progestins were associated with significantly lower gonadotrophin consumption than the long GnRH agonist protocol (mean difference (MD) = -648, 95% CI = -746 to -550 IU) and significantly higher gonadotrophin consumption than the short GnRH agonist protocol (MD = 433, 95% CI = 311 to 555 IU). Overall, live birth, ongoing and clinical pregnancy rates per ET were similar with progestins and GnRH analogues. However, when progestins were compared with GnRH agonists, sensitivity analyses including women with polycystic ovary syndrome (risk ratio (RR) = 1.27, 95% CI = 1.06 to 1.53) and short GnRH agonist protocols (RR = 1.14, 95% CI = 1.02 to 1.28) showed significantly higher clinical pregnancy rates with progestins. However, the quality of evidence is low. Studies comparing medroxyprogesterone acetate, dydrogesterone and micronized progesterone suggested similar ovarian response and pregnancy outcomes. The euploidy status of embryos from progestin primed cycles was similar to that of embryos from conventional stimulation cycles. Available information is reassuring regarding obstetric and neonatal outcomes with the use of progestins. Despite the lower cost of progestins than GnRH analogues, the mandatory cryopreservation of all embryos followed by a deferred transfer may increase cost per live birth with progestins as compared to an ART cycle culminating in a fresh ET.

WIDER IMPLICATIONS

Progestins can present an effective option for women who do not contemplate a fresh ET, e.g. fertility preservation, anticipated hyper responders, preimplantation genetic testing, oocyte donors, double stimulation cycles.

There is a cycle to cycle variation in ovarian response and pre-hCG serum progesterone level: an analysis of 244 consecutive IVF cycles

We aimed to answer one key question, that was not previously addressed as to whether serum progesterone (P_4-hCG day) and its co-variates (estradiol (E_{2-hCG day}) and the number of retrieved oocytes) of a given cycle can be predictive of the subsequent cycle when both cycles are consecutive and comparable for the stimulation protocol, gonadotropin dose and duration of stimulation. We analyzed such 244 consecutive (< 6 months) IVF cycles in 122 patients with GnRH agonist long protocol and found that P₄, E₂ and the number of retrieved oocytes significantly vary between the two cycles. Although P₄ increased (ranging from 4.7 to 266.7%) in the 2nd cycle in 61 patients, E₂ and the number of retrieved oocytes, which are normally positively correlated with P₄ paradoxically decreased in the 41% and 37.7% respectively, of these same 61 patients. When a similar analysis was done in the 54 out of 122 patients (44.3%) in whom serum P₄ was decreased in the 2nd cycle, the mean decrease in P₄ was − 34.1 ± 23.3% ranging from − 5.26 to − 90.1%. E₂ and the number of retrieved oocytes paradoxically increased in the 42.3% and 40.7% of these 54 patients respectively. P₄ remained the same only in the 7 (5.7%) of these 122 patients. These findings indicate that late follicular phase serum P₄ may change unpredictably in the subsequent IVF cycle. The changes are not always necessarily proportional with ovarian response of previous cycle suggesting that growth characteristics and steroidogenic activities of antral cohorts may exhibit considerable cycle to cycle variations.

Should we still perform fresh embryo transfers in ART?

An increasing number of researchers have alluded to the potential benefit of deferring the transfer of embryos produced during assisted reproductive technologies (ARTs) away from ovarian stimulation, using cryopreservation to enable this. The scientific evidence that may justify this recent trend in the use of the so-called 'freeze-all strategy' includes early, mostly small randomised controlled trials that have demonstrated an increase in live birth rates after elective embryo cryopreservation in certain patient populations, as well as evidence from cohort studies and retrospective analyses. What are the risks and benefits of freeze-all strategies in ART, who are the patients in whom it is likely to be advantageous, and does the current evidence allow us to identify situations when deciding that a fresh embryo transfer would be counter-productive? ART professionals are often faced with challenging clinical decisions regarding the best course of treatment for their patient. The purpose of this opinion paper is to provide a clinical guide for whether to perform a fresh embryo transfer or to opt for freezing all embryos in specific situations.