Association Between Progesterone Elevation on the Day of Human Chronic Gonadotropin Trigger and Pregnancy Outcomes After Fresh Embryo Transfer in In Vitro Fertilization/Intracytoplasmic Sperm Injection Cycles

Predictive Role of Progesterone Levels for IVF Outcome in Different Phases of Controlled Ovarian Stimulation for Patients With and Without Endometriosis: Expert View

The study aimed to review the role of basal, trigger, and aspiration day progesterone levels (PLs) as predictors of in vitro fertilization (IVF) success for patients with and without endometriosis. A non-systematic review was conducted by searching papers published in English during the period of 1990-2023 in MEDLINE and PubMed, Embase, The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register), and Web of Science. The most widely used IVF predictor success was the trigger day progesterone serum level. Many studies utilize the threshold level of 1.5-2.0 ng/ml. However, the predictive power of only progesterone level failed to show high sensitivity and specificity. Contrary, progesterone level on the trigger day combined with the number of mature retrieved oocytes had the highest predictive power. High baseline progesterone level was associated with poor IVF outcomes. Research on progesterone and IVF success in patients with endometriosis is limited but indicates that endometriosis patients seem to benefit from higher progesterone concentrations (≥ 37.1 ng/ml) in IVF cycles. Currently, there is limited data for a definitive insight into the mportance of progesterone in the estimation of IVF success. Nonetheless, this summarized evidence could serve as up-to-date guidance for the role of progesterone in the prediction of IVF outcomes, both in patients with and without endometriosis.

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.

Effect of serum progesterone on human chorionic gonadotropin trigger day / metaphase II oocyte ratio on pregnancy and neonatal outcomes in women undergoing ICSI cycle

BACKGROUND

The serum progesterone on human chorionic gonadotropin trigger day / metaphase II oocyte (P/MII) ratio might be a more predictable indicator of pregnancy and neonatal outcomes as compare to P/estradiol (E2) or P alone. Hence, we conducted a larger population study to compare the pregnancy and neonatal outcomes in the low and high P/MII ratio.

METHODS

A retrospective, single-center, larger population cohort study between January 2015 and August 2021. Calculate the threshold effect of P/MII ratio on clinical pregnancy rate according to the construct smooth curve fitting. Divide data into two groups by threshold for comparison.

RESULTS

3566 fresh ICSI-ET cycles were included, in which 929 singleton delivery and 676 twin deliveries. Compare to P/MII ≤ 0.367 group, it indicated that the P/MII > 0.367 group had a lower clinical pregnancy rate and live birth rate, furthermore, a significantly higher rate of LBW and SGA were observed in the singleton and twin deliveries. No deleterious impact of high P/MII ratio on embryo quality and undesirable pregnancy outcomes was shown.

CONCLUSIONS

When P/MII is higher than 0.367, may have adverse impacts on pregnancy and neonatal outcomes for ICSI cycle.

The Impact of Late Follicular Phase Progesterone Elevation on Cumulative Live Birth Rate and Embryo Quality in 4072 Freeze-All Cycles

Late follicular phase progesterone elevation during in vitro fertilization impedes embryo implantation. It is unclear whether late follicular phase progesterone elevation still has a negative effect on cumulative live births and embryo quality when a freeze-all strategy is adopted. Data from a total of 4072 patients were reviewed. All patients used the freeze-all strategy. Multivariate regression analyses were used to assess the association of progesterone levels with both cumulative live birth and embryo quality. There was no significant difference in the cumulative live birth rate between the groups with progesterone level <1.5 ng/mL and ≥1.5 ng/mL. The progesterone level was not associated with cumulative live birth and embryo quality.

Prediction of Fertilization Disorders in the In Vitro Fertilization/Intracytoplasmic Sperm Injection: A Retrospective Study of 106,728 Treatment Cycles

Purpose

This study aimed to develop a risk prediction of fertilization disorders during the in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

Methods

A retrospective study was performed with 106,728 fresh embryo IVF/ICSI cycles from 2009 to 2019. Basic characteristics of patients, clinical treatment data, and laboratory parameters were involved. The associations between the selected variables and risks for low fertilization rate (LFR) and total fertilization failure (TFF) were investigated. Ordinal logistic regression and the receiver operating characteristic curves (ROCs) were used to construct and evaluate the prediction models.

Results

A total of 97,181 controls, 4,343 LFR and 5,204 TFF cases were involved in this study. The model based on clinical characteristics (the ages of the couples, women's BMI, types of infertility, ART failure history, the diminished ovarian reserve, sperm quality, insemination method, and the number of oocytes retrieved) had an AUC of 0.743 for TFF. The laboratory model showed that primary infertility, ART failure history, minimal-stimulation cycle/natural cycle, numbers of oocyte retrieved < 5, IVF, and Anti-Mullerian hormone (AMH) level < 1.1ng/ml are predictors of TFF, with an AUC of 0.742.

Conclusion

We established a clinical and a laboratory prediction model for LFR/TFF. Both of the models showed relatively high AUCs.

Effects of half-dose and full-dose GnRH antagonists on IVF-ET outcomes: a retrospective study

Background

Gonadotropin-releasing hormone antagonist(GnRH-ant) has been shown to have a negative effect on endometrial receptivity. Therefore, the use of lower doses of GnRH-ant during controlled ovarian stimulation (COS) may improve endometrial receptivity and clinical pregnancy rate. However, the GnRH-ant dose is relatively flexible and there is no fixed requirement for guidance. In this retrospective study, we determined the effects of half-dose and full-dose GnRH-ant on IVF-ET outcomes.

Methods

Of the 316 cycles in the 314 patients analyzed in this study, 149 received GnRH-ant half-dose (Group1), while 167 received GnRH-ant full-dose (Group2). The groups were further classified based on age and BMI. Age subgroups, were divided as age ≤ 35(subgroup A) and age > 35(subgroup B): 180 cycles in subgroup A (107 cycles in subgroup A1,73 cycles in subgroup A2), 136 cycles in subgroup B (42 cycles in subgroup B1,94 cycles in subgroupB2). The subgroups based on BMI were divided as BMI < 25 (subgroup C)and BMI ≥ 25 (subgroup D):208 cycles in subgroup C (94 cycles in subgroup C1,114 cycles in subgroup C2), 108 cycles in subgroup D (55 cycles in subgroup D1,53 cycles in subgroup D2).

Results

The number of fertilized oocytes, superior-quality embryos, clinical pregnancy rate, and live birth rate differed significantly between the two groups. However, the number of retrieved oocytes and available embryos were significantly higher in Group 1 than Group 2 (8.17 ± 4.10 vs. 7.07 ± 4.05, 2.96 ± 2.03 vs. 2.52 ± 1.62, respectively,p<0.05). Differences between the age subgroups were not statistically significant. However, in the subgroups based on BMI, the fertilized oocytes, available embryos, the number of superior-quality embryos, and the live birth rate differed significantly between the four subgroups. The number of retrieved oocytes was higher in subgroup C1 than in subgroup C2 (8.24 ± 4.04 vs. 6.83 ± 3.92,p < 0.05), In addition, the clinical pregnancy rate was slightly higher in subgroup D1 than in subgroup D2(45.45 vs. 24.53%, P < 0.05).

Conclusions

The results showed that half-dose GnRH-ant was as effective as full-dose GnRH-ant for most patients. Moreover, half-dose GnRH-ant may be more suitable in patients with BMI greater than or equal to 25. The findings of this study need to be validated in a large sample RCT.

Trial registration

Retrospectively registered.

Endometrial Receptivity Testing and Therapy in Assisted Reproductive Treatment

Assisted reproductive treatment (ART) gave numerous couples the chance to have their biological child. Improvement in laboratory and culture conditions allows for selection of embryos with the best developmental potential, although replacement of these top-quality embryos does not, however, guarantee reproductive success. Endometrial receptivity is essential for pregnancy establishment and may be the limiting factor for the observed pregnancy rates with ART. Multiple modalities have been in use to assess endometrial receptivity, with ultrasound assessment of the endometrial morphology most commonly used due to its noninvasive nature and availability. Utilization of various "omics" increases our understanding of endometrial receptivity and selectivity; however, significantly more work is required to develop clinically relevant and validated tests of endometrial receptivity and treatments which could improve a suboptimal endometrial milieu. Current evidence for and against use of various tests of endometrial receptivity in women undergoing ART is presented in this article.

Thicker endometrium on hCG trigger day improves the live birth rate of fresh cleavage embryo transfer in GnRH-agonist regimen of normogonadotrophic women

Background

Luteinizing hormone (LH) and progesterone (PROG) on human chorionic gonadotropin (hCG) trigger day are significantly correlated with assisted reproductive technology (ART) outcome. Moreover, LH and PROG are also involved in the functional preparation of the endometrium during the implantation window; however, whether they are related to endometrial thickness (EMT) is still unknown. The aim of the present study was to assess whether EMT has a positive correlation on the live birth rate following fresh embryo transfer (ET), and whether LH and PROG have an impact on EMT.

Methods

A total of 2,260 normogonadotrophic women were treated with a GnRH agonist for in vitro fertilization (IVF)/intracytoplasmic sperm injection. Patients with advanced age and poor ovarian reserve were excluded. The levels of LH, PROG, and EMT on the hCG trigger day were divided into binary variables, respectively, by the cutoff values, and which were obtained based on receiver operating characteristic curve analysis of live birth among LH, PROG and EMT levels on the hCG trigger day, respectively. Multivariate binary logistic regression was used to confirm the role of LH, PROG, and EMT on the live birth, and stratified analysis was used to determine whether LH and PROG have an impact on EMT.

Results

EMT and LH were protective factors for live births, with odds ratios (OR) of 1.11 [95% confidence interval (CI): 1.066–1.157] and 1.696 (95% CI: 1.345–2.139), respectively. However, PROG was a risk factor for live birth, with an OR of 0.635 (95% CI: 0.526–0.766). The hierarchical cross-table analysis indicated that EMT had no significant difference for live birth in the combination of low LH and high PROG group. In the other subgroups, thick EMT was associated with a higher live birth rate (P<0.05).

Conclusions

On hCG trigger day, EMT, LH, and PROG all were independent factors that affected the live birth of fresh ETs. Thick EMT can significantly increase the live birth rate. However, multivariate logistic regression analysis showed that EMT does not affect the live birth rate in combination of low LH and high PROG environment.

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.

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.

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).

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

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Stop GnRH-Agonist Combined with Multiple-Dose GnRH-Antagonist for Patients with Elevated Peak Serum Progesterone Levels Undergoing Ovarian Stimulation for IVF: A Proof of Concept

AIM

The aim of the study was to examine whether the Stop GnRH-agonist combined with multiple-dose GnRH-antagonist protocol may overcome progesterone elevation during the late follicular phase.

PATIENTS AND METHODS

A cohort historical, proof of concept study consisting of 11 patients with progesterone elevation (>3.1 nmol/L) during conventional IVF/intracytoplasmic sperm injection (ICSI), who underwent a subsequent Stop GnRH-agonist combined with multiple-dose GnRH-antagonist ovarian stimulation (OS) protocol, within 3 months of the previous failed conventional IVF/ICSI cycle.

RESULTS

The Stop GnRH-agonist combined with multiple-dose GnRH-antagonist COH protocol revealed significantly lower peak progesterone levels, with significantly higher numbers of follicles >13 mm in diameter on the day of hCG administration, oocytes retrieved, mature oocytes, and top-quality embryos, with an acceptable clinical pregnancy rate (18.2%).

CONCLUSIONS

The combined Stop GnRH-ag/GnRH-ant OS protocol is a valuable tool in the armamentarium for treating patients with progesterone elevation during the late follicular phase. Further large prospective studies are needed to validate our observation and to characterize the appropriate patients' subgroup, which might benefit from the combined Stop GnRH-ag/GnRH-ant COH protocol.

Role of gene polymorphisms related to progesterone elevation in women undergoing long GnRH agonist protocols

RESEARCH QUESTION

Can single-nucleotide polymorphisms (SNP) of genes related to progesterone synthesis predict the risk of premature serum progesterone elevation in women undergoing gonadotrophin-releasing hormone agonist protocols for ovarian stimulation?

DESIGN

A total of 765 women were divided into high progesterone and normal progesterone groups according to progesterone concentration on the day of human chorionic gonadotrophin (HCG) administration, with the 75th percentile as the threshold between the group. Associations were analysed of genetic information from whole exome sequencing and the clinical characteristics of the two groups to identify the relationship between SNP, haplotypes and serum progesterone elevation.

RESULTS

Among 40 common SNP of eight genes (FSHR, LHCGR, ESR1, ESR2, PGR, HSD3B1, CYP11A1 and CYP17A1), no statistical significance between the high and normal progesterone groups was identified in the distribution of genotypes and allele frequencies after multiple test correction to adjust the false discovery rate (P_FDR > 0.05). When compared with the most common haplotypes of each gene, haplotype GAAG in CYP17A1 was associated with a 1.44-fold increased risk of progesterone elevation (95% confidence interval [CI] 1.22-1.69, P_FDR < 0.001), while haplotypes of the following genes showed a decreased risk of progesterone elevation: haplotype CC in FSHR and LHCGR (0.66-fold, P_FDR = 0.020, and 0.64-fold, P_FDR < 0.001, respectively), CA in ESR1 (0.90-fold, P_FDR < 0.001), TCTGG in ESR2 (0.92-fold, P_FDR = 0.007) and GAACC in HSD3B1 (0.42-fold, P_FDR < 0.001).

CONCLUSIONS

Polymorphism in genes involved in enzymes or hormone receptors in the progesterone synthesis pathway may have a role in modifying risk of serum progesterone elevation.

Do serum progesterone levels on day of embryo transfer influence pregnancy outcomes in artificial frozen-thaw cycles?

PURPOSE

The purpose of this study is to investigate whether progesterone (P4) levels on the day of frozen-thawed embryo transfer (FET) to a hormonally prepared endometrium correlate with pregnancy outcomes.

METHODS

This is a large retrospective cohort analysis comprising of N = 2010 FETs. In these cycles, P4 levels on the day of transfer were assessed in relation to pregnancy outcomes. A threshold of 10 ng/mL was used to simulate currently accepted levels for physiological corpus luteal function. Biochemical pregnancy, clinical pregnancy, and live birth rates were compared between those with P4 levels above and below this threshold. Analyses using transfer day P4 thresholds of 5 ng/mL and 20 ng/mL were then completed to see if these could create further prognostic power.

RESULTS

When comparing FET outcomes in relation to P4 levels < 10 ng/mL and ≥ 10 ng/mL, we observed no differences in biochemical pregnancy rates (39.53% vs. 40.98%, p = 0.52), clinical pregnancy rates (20.82 vs. 22.78, p = 0.30), and live birth rates (14.25 vs. 16.21 p = 0.23). In patients whose P4 met the threshold of 20 ng/mL, there was similarly no statistically significant improvement in pregnancy outcomes. While there was no difference for biochemical or clinical pregnancy rates, a statistically significant improvement in live birth rates was observed for those with a transfer day P4 level ≥ 5 ng/mL.

CONCLUSIONS

We demonstrated that P4 levels at or above 10 ng/mL on the day of FET do not confer a statistically significant improvement in pregnancy outcomes. P4 below 5 ng/mg was associated with lower live birth rates suggesting that there is a threshold below which it is difficult to salvage FET cycles.

Progesterone Elevation and Preventive Strategies to Avoid Implantation Failure

Despite the wide utilization of gonadotropin-releasing hormone analogs, progesterone elevation (P₄E) in the late follicular phase occurs in 5 to 30% of all ovarian stimulation (OS) cycles. Although the detrimental effect of P₄E on pregnancy rates in fresh in vitro fertilization cycles is valid in all subsets of cases, higher levels of P₄ and a longer duration of P₄E may be needed in patients with a hyper-ovarian response in order for a negative impact on pregnancy rates to occur. Available preclinical and clinical data suggest that aggressive OS with high doses of follicle-stimulating hormone might increase 3β-hydroxy steroid dehydrogenase and 17β-hydroxy steroid dehydrogenase enzyme activity in human granulosa cells, which leads to high P₄ production and hence a higher amount of leakage to the systemic circulation due to a lack of 17α-hydroxylase enzyme expression in human species. High P₄ concentrations appear to alter gene expression in the endometrium; however, caution is necessary regarding its potential effect on oocyte/embryo quality with respect to the role of inherent follicular disruption in some women. In terms of the mechanism of overproduction in P₄ synthesis, the main preventive strategy should be avoiding aggressive stimulation. Unfortunately, there is lack of large-scale randomized controlled trials for other approaches, including deferred embryo transfer in the thaw cycle. Since there is a significant inter-assay variability for P₄ measurement, it may be wise to recommend that every center should define their own P₄E and the level needed for harm to occur based on their own assays and datasets before deciding the best approach.

Clinically significant intra-day variability of serum progesterone levels during the final day of oocyte maturation: a prospective study with repeated measurements

STUDY QUESTION

Is there significant variability in progesterone levels during the final day of oocyte maturation in women undergoing ovarian stimulation?

SUMMARY ANSWER

Progesterone levels drop from the basal level up to 44% during the final day of oocyte maturation in women undergoing ovarian stimulation.

WHAT IS KNOWN ALREADY

It has been suggested that elevated progesterone levels on the final day of ovarian stimulation may be related to poorer outcomes in in vitro fertilization fresh cycles due to a negative impact on the endometrium. However, despite conflicting results regarding the actual effect of progesterone on pregnancy rates and the lack of a well-established cut off, currently many IVF patients have their embryo transfer deferred when progesterone values surpass a threshold of 1.5 ng/ml on the day of ovulation triggering.

STUDY DESIGN, SIZE, DURATION

This was a prospective cohort study conducted in 22 oocyte donors of a university-affiliated fertility centre between November 2017 and January 2018. We calculated the sample size to detect a difference of 15% between the first and last progesterone measurements with a 5% false-positive rate in a two-sided test with 80% statistical power and a 95% confidence interval (CI).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Progesterone circulating levels were evaluated at four different times during the final day of oocyte maturation (08:00, 12:00, 16:00 and 20:00) before ovulation triggering in healthy oocyte donors. A flexible antagonist protocol was used, and ovarian stimulation was achieved with recombinant follicle-stimulating hormone (FSH) in all cases. The pairwise percentage differences in progesterone levels for each patient were calculated. Univariate linear regression analysis was adopted in order to evaluate variables associated with progesterone levels on the first measurement. The intra-day variability of progesterone was analysed using mixed models.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean serum progesterone values at 08:00, 12:00, 16:00 and 20:00 were 1.75 ng/ml, 1.40 ng/ml, 1.06 ng/ml and 0.97 ng/ml. The progesterone difference between 08:00 and 20:00 was 0.77 (95% CI, 0.56–0.99), which is equivalent to a 44% decline in the mean progesterone values between the first (08:00) and the last determination (20:00; P < 0.001). Among those patients with basal (08:00) progesterone levels >1.5 ng/ml (n = 10), 70% (n = 7) showed levels reduced to <1.5 ng/ml on the last determination of the day (20:00). A mixed model analysis revealed that the progesterone reduction during the day was significantly associated with time and total recombinant FSH dose administered.

LIMITATIONS, REASONS FOR CAUTION

Only young healthy oocyte donors stimulated with an antagonist protocol using recombinant FSH were included. Extrapolation to the general IVF population, with different stimulation protocols and gonadotropins, needs to be confirmed.

WIDER IMPLICATIONS OF THE FINDINGS

This study suggests that a single progesterone determination on the final day of oocyte maturation is not reliable enough to make clinical decisions due to the enormous variation in progesterone during the day. Further studies are needed to better define the impact of the follicular progesterone rise on the endometrium of IVF cycles.

STUDY FUNDING/COMPETING INTEREST(S)

Funding was granted from Fundació Santiago Dexeus Font. N.P.P. received unrestricted grants and/or lectures fees from Roche Diagnostics, MSD, Merck, Ferring Pharmaceuticals, IBSA, Theramex and BESINS International, not associated with the current study. The remaining authors have no competing interests.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT03366025.

Flexible Low-Dose GnRH Antagonist Protocol Is Effective in Patients With Sufficient Ovarian Reserve in IVF

Gonadotropin-releasing hormone antagonist (GnRH-ant) has been shown to negatively influence endometrial receptivity. Reducing the GnRH-ant dose during controlled ovarian stimulation (COS) when using a GnRH-ant protocol may be beneficial to embryo implantation. However, whether or not the minimum daily GnRH-ant dose should be individualized remains uncertain. In this retrospective study, we aimed to elucidate the feasibility and effectiveness of moderately reducing the daily GnRH-ant dose to 0.125 mg, and then adjusting the dose to 0.25 mg based on subsequent luteinizing hormone (LH) levels. Of the 434 patients analyzed in this study, 209 received our new flexible low-dose GnRH-ant protocol (Group 1) and 225 received a conventional GnRH-ant protocol with a fixed daily dose of 0.25 mg (Group 2). Furthermore, 105 and 114 cycles from groups 1 and 2 received fresh embryo transfer. In Group 1, 30 patients whose dose of 0.125 mg GnRH-ant was adjusted according to their LH levels and 179 patients who received consistently low doses were further divided into subgroups 1 and 2, respectively. Neither the number of retrieved oocytes and available embryos nor the implantation rate, clinical pregnancy rate, and ongoing pregnancy rate significantly differed between the two groups. However, GnRH-ant dose and stimulation duration were much lower and shorter in Group 1 than in Group 2 (p < 0.05). Subgroup 1 exhibited higher basal follicle-stimulating hormone (FSH) and lower antral follicle count (AFC) than subgroup 2 significantly. The number of retrieved oocytes and available embryos were lower in subgroup 1 than in subgroup 2 (6.83 ± 3.28 vs. 11.83 ± 4.82, 2.93 ± 1.86 vs. 4.99 ± 3.46, respectively, p < 0.05), while more canceled cycles for pre-ovulation occurred in subgroup 1 than in subgroup 2 (3/30 vs. 1/179, p < 0.05). The results showed that the flexible low-dose GnRH-ant protocol was as effective as the conventional fixed-dose GnRH-ant protocol with 0.25 mg per day for most patients with normal ovarian reserve. This retrospective analysis and the small sample size are the main limitations of this study, and a large sample RCT will be carried out in the future.