The curious case of premature luteinization

A Dose-Response Study on Functional and Transcriptomic Effects of FSH on Ex Vivo Mouse Folliculogenesis

Follicle-stimulating hormone (FSH) binds to its membrane receptor (FSHR) in granulosa cells to activate various signal transduction pathways and drive the gonadotropin-dependent phase of folliculogenesis. Both FSH insufficiency (due to genetic or nongenetic factors) and FSH excess (as encountered with ovarian stimulation in assisted reproductive technology [ART]) can cause poor female reproductive outcomes, but the underlying molecular mechanisms remain elusive. Herein, we conducted single-follicle and single-oocyte RNA sequencing analysis along with other approaches in an ex vivo mouse folliculogenesis and oogenesis system to investigate the effects of different concentrations of FSH on key follicular events. Our study revealed that a minimum FSH threshold is required for follicle maturation into the high estradiol-secreting preovulatory stage, and such threshold is moderately variable among individual follicles between 5 and 10 mIU/mL. FSH at 5, 10, 20, and 30 mIU/mL induced distinct expression patterns of follicle maturation-related genes, follicular transcriptomics, and follicular cAMP levels. RNA sequencing analysis identified FSH-stimulated activation of G proteins and downstream canonical and novel signaling pathways that may critically regulate follicle maturation, including the cAMP/PKA/CREB, PI3K/AKT/FOXO1, and glycolysis pathways. High FSH at 20 and 30 mIU/mL resulted in noncanonical FSH responses, including premature luteinization, high production of androgen and proinflammatory factors, and reduced expression of energy metabolism-related genes in oocytes. Together, this study improves our understanding of gonadotropin-dependent folliculogenesis and provides crucial insights into how high doses of FSH used in ART may impact follicular health, oocyte quality, pregnancy outcome, and systemic health.

Premature luteinization and pregnancy outcomes in depot goserelin-downregulated assisted reproductive technology cycles: A cross-sectional study from Ethiopia

OBJECTIVE

To compare the rate of premature luteinization in depot goserelin-downregulated in vitro fertilization (IVF) cycles with other IVF protocols at a teaching hospital in Ethiopia.

METHODS

We conducted a cross-sectional study on the effects of premature luteinization on IVF outcomes at St. Paul's Hospital Millennium Medical College, a tertiary teaching hospital in Ethiopia. Patients who had IVF at this hospital between 2019 and 2020 were included in the study. Patient records were reviewed and collected on Open Data Kit. We used Stata release 15 to analyze the data. A simple descriptive analysis and bivariate analysis  were performed as appropriate. A P-value less than 0.05 was considered as statistically significant.

RESULTS

A total of 305 patients (40 cases with premature luteinization and 265 without premature luteinization) were included. There was no difference in the rate of premature luteinization in the depot goserelin long protocol cycles (6.4%), compared to minimal stimulation (14.1%) and antagonist protocols (16.7%), P = 0.19. Embryo transfer was carried out in 27 (67.5%) patients in the premature luteinization group, which was lower than the 86.0% (228/265) in the non-premature luteinization group, P = 0.003. There was no difference in the median number of oocytes retrieved (8.5 [interquartile range 5.0, 13.0] per cycle in the premature luteinization group vs 5.0 [interquartile range 3.0, 10.0] in those without premature luteinization, P = 0.10).

CONCLUSION

A depot goserelin-downregulated long protocol for IVF is a cost-effective and convenient option for controlled ovarian hyperstimulation without increased risk of having premature luteinization compared to antagonist and minimal stimulation protocols.

Follicular Hyperstimulation Dysgenesis: New Explanation for Adverse Effects of Excessive FSH in Ovarian Stimulation

High follicle-stimulating hormone (FSH) doses during ovarian stimulation protocols for assisted reproductive technologies (ART) are detrimental to ovulatory follicle function and oocyte quality. However, the mechanisms are unclear. In a small ovarian reserve heifer model, excessive FSH doses lead to phenotypic heterogeneity of ovulatory size follicles, with most follicles displaying signs of premature luteinization and a range in severity of abnormalities. By performing whole transcriptome analyses of granulosa cells, cumulus cells, and oocytes from individual follicles of animals given standard or excessive FSH doses, we identified progressive changes in the transcriptomes of the 3 cell types, with increasing severity of follicular abnormality with the excessive doses. The granulosa and cumulus cells each diverged progressively from their normal phenotypes and became highly similar to each other in the more severely affected follicles. Pathway analysis indicates a possible dysregulation of the final stages of folliculogenesis, with processes characteristic of ovulation and luteinization occurring concurrently rather than sequentially in the most severely affected follicles. These changes were associated with disruptions in key pathways in granulosa and cumulus cells, which may account for previously reported reduced estradiol production, enhanced progesterone and oxytocin production and diminished ovulation rates. Predicted deficiencies in oocyte survival, stress response, and fertilization suggest likely reductions in oocyte health, which could further compromise oocyte quality and ART outcomes.

Excessive follicle-stimulating hormone during ovarian stimulation of cattle may induce premature luteinization of most ovulatory-size follicles†

High follicle-stimulating hormone (FSH) doses during ovarian stimulation are detrimental to ovulatory follicle function and decrease live birth rate in cattle and women. However, the mechanism whereby excessive FSH causes ovarian dysfunction is unknown. This study tested the hypothesis that excessive FSH during ovarian stimulation induces premature luteinization of ovulatory-size follicles. Small ovarian reserve heifers were injected twice daily for 4 days with 70 IU (N = 7 heifers) or 210 IU (N = 6 heifers) Folltropin-V [commercial FSH-enriched preparation of porcine pituitary glands with minor (<1%) luteinizing hormone (LH) contamination, cpFSH]. Ovulatory-size (≥10 mm) follicles were excised from ovaries after the last cpFSH injection and hormone concentrations in follicular fluid (FF) were determined using ELISA. Luteinization was monitored by assessing cumulus cell-oocyte complex (COC) morphology and measuring concentrations of estradiol (E), progesterone (P), and oxytocin (O) in FF. COCs were classified as having compact (cCOC) or expanded (eCOC) cumulus cell layers, and as estrogen-active (E:P in FF ≥1), estrogen-inactive (EI, E:P in FF ≤1 > 0.1), or extreme-estrogen-inactive (EEI, E:P in FF ≤0.1). A high proportion (72%) of ovulatory-size follicles in 210 IU, but not 70 IU, dose heifers displayed eCOCs. The high doses also produced higher proportions of EI or EEI follicles which had lower E:P ratio and/or E but higher P and/or O concentrations compared with the 70 IU dose heifers. In conclusion, excessive cpFSH doses during ovarian stimulation may induce premature luteinization of most ovulatory-size follicles in heifers with small ovarian reserves.

Regulatory Role and Potential Importance of GDF-8 in Ovarian Reproductive Activity

Growth differentiation factor-8 (GDF-8) is a member of the transforming growth factor-beta superfamily. Studies in vitro and in vivo have shown GDF-8 to be involved in the physiology and pathology of ovarian reproductive functions. In vitro experiments using a granulosa-cell model have demonstrated steroidogenesis, gonadotrophin responsiveness, glucose metabolism, cell proliferation as well as expression of lysyl oxidase and pentraxin 3 to be regulated by GDF-8 via the mothers against decapentaplegic homolog signaling pathway. Clinical data have shown that GDF-8 is expressed widely in the human ovary and has high expression in serum of obese women with polycystic ovary syndrome. GDF-8 expression in serum changes dynamically in patients undergoing controlled ovarian hyperstimulation. GDF-8 expression in serum and follicular fluid is correlated with the ovarian response and pregnancy outcome during in vitro fertilization. Blocking the GDF-8 signaling pathway is a potential therapeutic for ovarian hyperstimulation syndrome and ovulation disorders in polycystic ovary syndrome. GDF-8 has a regulatory role and potential importance in ovarian reproductive activity and may be involved in folliculogenesis, ovulation, and early embryo implantation.

Self-Monitoring of Urinary Hormones in Combination with Telemedicine - a Timely Review and Opinion Piece in Medically Assisted Reproduction

Cycle monitoring via ultrasound and serum-based hormonal assays during medically assisted reproduction (MAR) can provide information on ovarian response and assist in optimizing treatment strategies in addition to reducing complications such as ovarian hyperstimulation syndrome (OHSS). Two surveys conducted in 2019 and 2020, including overall 24 fertility specialists from Europe, Asia and Latin America, confirmed that the majority of fertility practitioners routinely conduct hormone monitoring during MAR. However, blood tests may cause inconvenience to patients. The reported drawbacks of blood tests identified by the survey included the validity of results from different service providers, long waiting times and discomfort to patients due to travelling to clinics for tests and repeated venepunctures. Historically, urine-based assays were used by fertility specialists in clinics but were subsequently replaced by more practical and automated serum-based assays. A remote urine-based hormonal assay could be an alternative to current serum-based testing at clinics, reducing the inconvenience of blood tests and the frequency of appointments, waiting times and patient burden. Here we provide an overview of the current standard of care for cycle monitoring and review the literature to assess the correlation between urine-based hormonal assays and serum-based hormonal assays during MAR. In addition, in this review, we discuss the evidence supporting the introduction of remote urine-based hormonal monitoring as part of a novel digital health solution that includes remote ultrasound and tele-counselling to link clinics and patients at home.

A Case of Pre-Existing Pregnancy During an In-Vitro Fertilization Cycle

Serum progesterone levels performed prior to oocyte pick-up is commonly used to guide embryo transfer in in-vitro fertilization (IVF) cycles, as elevated levels can negatively influence pregnancy outcomes. However, levels associated with normal pregnancies should trigger clinicians to consider alternative causes such as a pre-existing pregnancy. We report a case of a 37-year-old patient who underwent controlled ovarian hyperstimulation in a gonadotrophin-releasing hormone antagonist cycle while having an undetected early pregnancy. No oocytes were retrieved at oocyte retrieval despite adequate follicular responses. Her serum progesterone level on the day of her trigger injection was 57.8 nmol/L. She was found to have a pregnancy of unknown location, detected 3 weeks after her oocyte retrieval and was subsequently treated with systemic methotrexate.

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.

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.

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.

Effect of Metformin on Premature Luteinization and Pregnancy Outcomes in Intracytoplasmic Sperm Injection-Fresh Embryo Transfer Cycles: A Randomized Double-Blind Controlled Trial

BACKGROUND

Premature luteinization (PL) is not unusual in in vitro fertilization (IVF) and could not be wholly avoided by using either gonadotropin-releasing hormone (GnRH) agonists or GnRH antagonist regimens. The study aims to evaluate metformin's efficacy in preventing PL in fresh GnRH antagonist intracytoplasmic sperm injection (ICSI) cycles with cleavage-stage embryo transfer.

MATERIALS AND METHODS

This randomized, double-blind, placebo-controlled trial was conducted in a tertiary university IVF center. We recruited infertile women who were scheduled to perform their first or second ICSI trial. Eligible women were recruited and randomized in a 1:1 ratio into two groups. Metformin was administered in a dose of 1500 mg per day since the start of contraceptive pills in the cycle antecedent to stimulation cycle until the day of ovulation triggering, while women in the placebo group received a placebo for the same regimen and duration. The primary outcome was the incidence of PL, defined as serum progesterone (P) on the triggering day ≥1.5 ng/mL. Secondary outcomes comprised the live birth, ongoing pregnancy, implantation, and good-quality embryos rates.

RESULTS

The trial involved 320 eligible participants (n=160 in each group). Both groups had comparable stimulation days, endometrial thickness, peak estradiol levels, number of oocytes retrieved, and number of mature oocytes. Metformin group experienced lower level of serum P (P<0.001) and incidence of PL (10 vs. 23.6%, P=0.001). Moreover, lower progesterone/estradiol (P/E) ratio and progesterone to mature oocyte index (PMOI) (P=0.002 and P=0.002, respectively) were demonstrated in women receiving metformin. Metformin group generated a better rate of goodquality embryos (P=0.005) and ongoing pregnancy (43.8 vs. 31.8%, P=0.026). A similar trend, though of borderline significance, was observed in the live birth rate in favor of metformin administration (38.15 vs. 27.5%, P=0.04).

CONCLUSION

Metformin could be used in patients with potential PL to improve fresh cycle outcomes by preventing PL (Registration number: NCT03088631).

New Human Follitropin Preparations: How Glycan Structural Differences May Affect Biochemical and Biological Function and Clinical Effect

It is well accepted that pituitary follitropin is secreted into the circulation as a mixture of variants, which differ not in primary structure but rather at the level of glycosylation. These glycosidic forms vary in the number of glycosylation sites filled, complexity of glycosidic chains, and sialylation and sulfation. It is generally agreed that high sialylation, 2,3 sialic acid capping of terminal N-acetyl galactosamine or galactose leads to longer circulating half-life, by blocking binding of asialoglycoprotein receptor (ASGPR) in the liver. In contrast, 2,6 sialic acid found in humans does not prevent recognition of galactose and N-acetyl galactosamine by ASGPR. Few studies on clinical outcomes comparing differences in sialylation of follitropin found in commercially available preparations are available. Thus, there is a clear need for a consortium of open data to address this unmet need. Recently, FSH glycosylation, primarily on the β-subunit, which varies as women age, has emerged as a key modifier of follitropin action, with profound biological effects in vivo in animal models. To date, limited information of recombinant follitropin hormone preparations is available. Thus, most of the studies with FSH that is well characterized biochemically have been done in vitro, with engineered non gonadal host cells bearing recombinant receptors or in animal models. Since limited studies in human granulosa cells are available, a question is whether structural differences in glycosylation in commercially available follitropin affects biological function and clinical effect in humans. The presence of fucose, for example, has not been studied greatly even though, in the case of antibody therapy it has been shown to have a large effect on antibody targeting. This review on glycosidic variability of follitropin from the biochemical/structural point of view reflects on this question and presents an assessment in the context of available published data. If clinical differences are to be expected or not, the readers will have a better understanding of the evidence for and limitations of such expectations.

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.

Cumulative Live Birth Rates After the First ART Cycle Using Flexible GnRH Antagonist Protocol vs. Standard Long GnRH Agonist Protocol: A Retrospective Cohort Study in Women of Different Ages and Various Ovarian Reserve

Objective: To compare the cumulative live birth rates (cLBRs) after the first assisted reproductive technology (ART) cycle using flexible gonadotropin releasing hormone (GnRH)-antagonist protocol vs. standard long GnRH agonist protocol for controlled ovarian stimulation (COS) in infertile women with different ages and ovarian reserve. Methods: Women who underwent ART treatment at our center between June 1st, 2015 and December 31st, 2018 were screened. Among them, only women who underwent their first COS cycle with flexible GnRH antagonist protocol or standard long GnRH agonist protocol were included in this study. The main outcome measurement was cLBR. Results: A total of 4,402 patients were eligible for the analysis, of whom, 2,762 patients used the GnRH agonist protocol and 1,640 patients used the GnRH antagonist protocol. The cLBRs of women in the antagonist protocol group and long agonist protocol group were 45.3 and 50.0%, respectively. Subgroup multivariable regression analysis showed that, in patients with low ovarian reserve (AFC ≤ 7), the cLBR was significantly lower in the antagonist group than in the long agonist protocol group [OR (95% CI) 0.62 (0.41, 0.94)], which effect was more robust in younger patients (<30 y) [OR (95% CI) 0.29 (0.11, 0.74)]. The analysis also revealed remarkably lower cLBR in patients above 40 years regardless of their AFC, although the difference was not statistically significant. However, in patients with high ovarian reserve (AFC >24), the cLBR was higher in cycles with antagonist protocol than with the long agonist protocol [OR (95% CI) 1.43 (0.96, 2.12)], and the effect was of statistical significance in younger patients (< 30 y) [OR (95% CI) 1.78 (1.07, 2.96)]. Conclusion: The present study suggests that the flexible GnRH antagonist protocol might not be suitable for patients with low ovarian reserve (AFC ≤ 7) or patients aged over 40 years. However, flexible GnRH antagonist protocol might be strongly recommended for patients under 30 years old and with high ovarian reserve (AFC > 24). For the rest groups of patients in the present cohort, antagonist protocol was slightly favored because it had lower OHSS in general and in patients with poly-cystic ovarian syndrome (PCOS) according to previous publications.

Revisiting debates of premature luteinization and its effect on assisted reproductive technology outcome

The impact of the prematurely elevated serum progesterone on the late follicular phase, commonly known as premature luteinization (PL), is a matter of continuing debate. Available evidence supports that serum progesterone ≥ 1.5 ng/ml on the day of ovulation triggering could reduce the pregnancy potential in fresh in vitro fertilization (IVF) cycles by jeopardizing endometrial receptivity. Causes of PL during ovarian stimulation are unclear. Recent studies point toward the daily follicle-stimulating hormone dosage, duration of controlled ovarian stimulation, number of oocytes retrieved, and peak estradiol level as factors affecting the incidence of PL. Emerging data show additional influence on embryo quality. The prevention of PL has been challenging. The key elements in preventing PL include individualization of ovarian stimulation according to patient's ovarian reserve, proper ovulation trigger timing, and use of medications such as corticosteroids and metformin. Embryo cryopreservation with deferred embryo transfer is the established strategy to overcome PL, yet it is an extra burden to the IVF laboratory and increased cost for patients. Herein, we review the up-to-date knowledge of this frequent IVF problem including causes, proposed diagnostic criteria, and its impact on endometrial receptivity, embryo quality, and pregnancy outcomes. The preventive measures and rescue strategies are also discussed.

[Effects of cetrorelix versus ganirelix in gonadotropin-releasing hormone antagonist cycles for preventing premature luteinizing hormone surges and on clinical outcomes of IVF-ET cycles]

OBJECTIVE

To compare the effects of cetrorelix and ganirelix in gonadotropin-releasing hormone antagonist (GnRH-ant) cycles for preventing premature luteinizing hormone (LH) surges and on clinical outcomes of IVF-ET cycles.

METHODS

We retrospectively analyzed 2572 GnRH-ant cycles of in vitro fertilization and embryo transfer from January, 2013 to December, 2016, including 1368 cycles with cetrorelix treatment and 1204 cycles with ganirelix treatment. The baseline characteristics of the patients and the clinical outcomes of the two groups were compared.

RESULTS

Compared with those receiving ganirelix treatment, the patients with cetrorelix treatment had a significantly younger age (33.10 vs 33.89 years, P < 0.001) and a lower body mass index (21.57 vs 21.84 kg/m2, P=0.024). After adjustment for age and body mass index of the patients, no significant differences were found between the two groups in the levels of follicle-stimulating hormone (FSH), LH, estradiol (E2), progesterone (P) levels either at the baseline or on the day of hCG triggering, or in the number of oocytes retrieved (P > 0.05). The two groups also had comparable percentages of patients with LH > 10 U/L on the day of hCG triggering (3.7% vs 3.2%) and similar spontaneous ovulation rate (0.6% vs 0.5%), clinical pregnancy rate (47.7% vs 45.9%) and live birth rate (37.5% vs 33.6%) following fresh embryo transfer (P > 0.05). The incidence of moderate to severe ovarian hyperstimulation syndrome, however, was significantly higher in ganirelix group than in cetrorelix group (0.7% vs 0.1%, P=0.006).

CONCLUSIONS

Cetrorelix and ganirelix can achieve comparable effects for preventing premature LH surges and can achieve similar clinical outcomes of GnRH-ant cycles, but ganirelix is associated with a significantly higher incidence of moderate to severe ovarian hyperstimulation syndrome.