Effect of preovulatory progesterone elevation and duration of progesterone elevation on the pregnancy rate of frozen–thawed embryo transfer in natural cycles

Contributing factors for pregnancy outcomes in women with PCOS after their first FET treatment: a retrospective cohort study

OBJECTIVE

We aim to explore the contributing factors of clinical pregnancy outcomes in PCOS patients undergoing their first FET treatment.

METHODS

A retrospective analysis was conducted on 574 PCOS patients undergoing their first FET treatment at a private fertility center from January 2018 to December 2021.

RESULTS

During the first FET cycle of PCOS patients, progesterone levels (aOR 0.109, 95% CI 0.018-0.670) and endometrial thickness (EMT) (aOR 1.126, 95% CI 1.043-1.419) on the hCG trigger day were associated with the clinical pregnancy rate. Similarly, progesterone levels (aOR 0.055, 95% CI 0.007-0.420) and EMT (aOR 1.179, 95% CI 1.011-1.376) on the hCG trigger day were associated with the live birth rate. In addition, AFC (aOR 1.179, 95% CI 1.011-1.376) was found to be a risk factor for preterm delivery.

CONCLUSIONS

In women with PCOS undergoing their first FET, lower progesterone levels and higher EMT on hCG trigger day were associated with clinical pregnancy and live birth, and AFC was a risk factor for preterm delivery. During FET treatment, paying attention to the patient's endocrine indicators and follicle status may have a positive effect on predicting and improving the pregnancy outcome of PCOS patients.

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

STUDY QUESTION

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

SUMMARY ANSWER

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

WHAT IS KNOWN ALREADY

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

STUDY DESIGN, SIZE, DURATION

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

PARTICIPANTS/MATERIALS, SETTING, METHODS

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

MAIN RESULTS AND THE ROLE OF CHANCE

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

LIMITATIONS, REASONS FOR CAUTION

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

WIDER IMPLICATIONS OF THE FINDINGS

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

STUDY FUNDING/COMPETING INTEREST(S)

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

TRIAL REGISTRATION NUMBER

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

TRIAL REGISTRATION DATE

21 November 2021.

DATE OF FIRST PATIENT’S ENROLLMENT

23 November 2021.

Initiating luteal phase support with sc progesterone based on low serum progesterone on the transfer day in true natural cycle frozen embryo transfers

Introduction

Concerning contemporary in-vitro fertilisation (IVF) practice, the use of frozen embryo transfer (FET) cycles has become more common than fresh transfers. Natural cycle (NC), programmed artificial cycle and mild stimulation cycle are primary endometrium preparation cycles. Monitoring serum progesterone levels in FET cycles are in the scope of current research focus. Low progesterone levels on the day of embryo transfer is presumed to negatively affect pregnancy outcomes, while progesterone supplementation may improve pregnancy rates. The purpose of our trial is to evaluate whether initiating subcutaneous (SC) progesterone supplementation on the day of embryo transfer when serum progesterone levels are below 10 ng/mL in tNC-FET will result in pregnancy rates comparable to those of patients with sufficient serum progesterone.

Methods

Retrospective single centre study was conducted between August 2022 and April 2023 with 181 tNC-FETs. Patients were separated into groups according to serum progesterone concentrations (≥10 ng/mL and <10 ng/mL) on embryo transfer (ET) day. S.c progesterone (25 mg) was given on the day of ET when serum progesterone was <10 ng/mL, continuing until the 10th gestational week. Blood samples for pregnancy tests were collected 12 days after ET. Outcome parameters were pregnancy rate, clinical pregnancy rate (CPR), miscarriage rate, multiple pregnancy rate, biochemical pregnancy, and ongoing pregnancy rate (OPR).

Results

About half (49.7%) had adequate progesterone concentrations (≥10ng/mL) on ET day. There was no significant difference between the groups regarding positive pregnancy test, OPR, multiple pregnancies, and miscarriage rates (57.8% versus 52.7%; 34.4% versus 29.7%, 1.1% versus 2.2%; 7.8% versus 5.5%; respectively, for progesterone concentrations on ET day ≥10 ng/mL and <10 ng/mL). With 55.2% of transfers leading to clinical pregnancy, significant differences emerged in biochemical pregnancy and CPR (3.3% vs 12.1%, P=0.02; 54.4% vs 40.7%, P=0.03, for ≥10 ng/mL and <10 ng/mL progesterone concentrations on ET day).

Discussion

This study indicates that nearly half of the tNC-FETs may need luteal phase support due to low progesterone. However, 25 mc sc progesterone rescued the luteal support and yielded similar OPR as compared to normal progesterone group. Further studies are needed for understanding optimal progesterone levels, supplementation effectiveness, and potential benefits of earlier supplementation in FETs.

The true natural cycle frozen embryo transfer - impact of patient and follicular phase characteristics on serum progesterone levels one day prior to warmed blastocyst transfer

BACKGROUND

In a true-natural cycle (t-NC), optimal progesterone (P4) output from the corpus luteum is crucial for establishing and maintaining an intrauterine pregnancy. In a previous retrospective study, low P4 levels (< 10 ng/mL) measured one day before warmed blastocyst transfer in t-NC were associated with significantly lower live-birth rates. In the current study, we aim to examine the relationship between patient, follicular-phase endocrine and ultrasonographic characteristics, and serum P4 levels one day prior to warmed blastocyst transfer in t-NC.

METHOD

178 consecutive women undergoing their first t-NC frozen embryo transfer (FET) between July 2017-August 2022 were included. Following serial ultrasonographic and endocrine monitoring, ovulation was documented by follicular collapse. Luteinized unruptured follicle (LUF) was diagnosed when there was no follicular collapse despite luteinizing-hormone surge (> 17 IU/L) and increased serum P4 (> 1.5 ng/mL). FET was scheduled on follicular collapse + 5 or LH surge + 6 in LUF cycles. Primary outcome was serum P4 on FET - 1.

RESULTS

Among the 178 patients, 86% (n = 153) experienced follicular collapse, while 14% (n = 25) had LUF. On FET-1, the median serum luteal P4 level was 12.9 ng/mL (IQR: 9.3-17.2), ranging from 1.8 to 34.4 ng/mL. Linear stepwise regression revealed a negative correlation between body mass index (BMI) and LUF, and a positive correlation between follicular phase peak-E2 and peak-P4 levels with P4 levels on FET-1. The ROC curve analyses to predict < 9.3 ng/mL (< 25th percentile) P4 levels on FET-1 day showed AUC of 0.70 (95%CI 0.61-0.79) for BMI (cut-off: 23.85 kg/m2), 0.71 (95%CI 0.61-0.80) for follicular phase peak-P4 levels (cut-off: 0.87 ng/mL), and 0.68 (95%CI 0.59-0.77) for follicular phase peak-E2 levels (cut-off: 290.5 pg/mL). Combining all four independent parameters yielded an AUC of 0.80 (95%CI 0.72-0.88). The adjusted-odds ratio for having < 9.3 ng/mL P4 levels on FET-1 day for patients with LUF compared to those with follicle collapse was 4.97 (95%CI 1.66-14.94).

CONCLUSION

The BMI, LUF, peak-E2, and peak-P4 levels are independent predictors of low serum P4 levels on FET-1 (< 25th percentile; <9.3 ng/ml) in t-NC FET cycles. Recognition of risk factors for low serum P4 on FET-1 may permit a personalized approach for LPS in t-NC FET to maximize reproductive outcomes.

Impact of progesterone concentration on human chorionic gonadotropin trigger day on clinical outcomes with one top-quality cleavage-stage embryo or blastocyst transfer in fresh in vitro fertilization cycles

Objective

To investigate the impact of the progesterone concentration on the human chorionic gonadotropin (hCG) trigger day on clinical outcomes with an antagonist protocol.

Methods

The retrospective cohort study included a total of 1,550 fresh autologous ART cycles with one top-quality embryo transfer. Multivariate regression analysis, curve fitting, and threshold effect analysis were performed.

Results

A significant association was found between the progesterone concentration and clinical pregnancy rate (adjusted OR, 0.77; 95% CI, 0.62-0.97; P = 0.0234), especially in blastocyst transfer (adjusted OR, 0.56; 95% CI, 0.39-0.78; P = 0.0008). The association between the progesterone concentration and the ongoing pregnancy rate was insignificant. The clinical pregnancy rate showed a linear relationship with an increased progesterone concentration in cleavage-stage embryo transfer. In blastocyst transfer, as the progesterone concentration increased, the clinical and ongoing pregnancy rates showed a parabolic reverse-U curve; the curve initially increased before declining at high progesterone concentrations. The clinical pregnancy rate increased with a progesterone concentration up to 0.80 ng/mL rather than tended to be stable. The clinical pregnancy rate significantly decreased when the progesterone concentration was ≥0.80 ng/mL.

Conclusion

The progesterone concentration on the hCG trigger day exhibits a curvilinear relationship with pregnancy outcomes in blastocyst transfer cycles, and the optimal threshold of the progesterone concentration is 0.80 ng/mL.

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

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

Effects of trigger-day progesterone in the preimplantation genetic testing cycle on the embryo quality and pregnancy outcomes of the subsequent first frozen-thawed blastocyst transfer

Objective

To assess whether progesterone (P) levels on the trigger day during preimplantation genetic testing (PGT) cycles are associated with embryo quality and pregnancy outcomes in the subsequent first frozen-thawed blastocyst transfer (FET) cycle.

Methods

In this retrospective analysis, 504 eligible patients who underwent ICSI followed by frozen-thawed embryo transfer (FET) with preimplantation genetic test (PGT) between December 2014 and December 2019 were recruited. All patients adopted the same protocol, namely, the midluteal, short-acting, gonadotropin-releasing hormone agonist long protocol. The cutoff P values were 0.5 and 1.5 ng/ml when serum P was measured on the day of human chorionic gonadotropin (HCG) administration, and cycles were grouped according to P level on the day of HCG administration. Furthermore, the effect of trigger-day progesterone on embryo quality and the subsequent clinical outcome of FET in this PGT population was evaluated.

Results

In total, 504 PGT cycles were analyzed. There was no significant difference in the number of euploid blastocysts, top-quality blastocysts, euploidy rate, or miscarriage rate among the three groups (P>0.05). The 2PN fertilization rate (80.32% vs. 80.17% vs. 79.07%) and the top-quality blastocyst rate (8.71% vs. 8.24% vs. 7.94%) showed a downward trend with increasing P, and the between-group comparisons showed no significant differences (P>0.05). The clinical pregnancy rate (41.25% vs. 64.79%; P<0.05) and live birth rate (35.00% vs. 54.93%; P<0.05) in subsequent FET cycles were substantially lower in the high-P group than in the P ≤ 0.5 ng/ml group. After adjustments were made for confounding variables, multivariate logistic regression analysis revealed that the high-P group had a lower clinical pregnancy rate (adjusted OR, 0.317; 95% CI, 0.145-0.692; P=0.004) and live birth rate (adjusted OR, 0.352; 95% CI, 0.160-0.773; P=0.009) than the low-P group in subsequent FET cycles, and the differences were significant.

Conclusions

This study demonstrates that in the PGT population, elevated P on the trigger day may diminish the top-quality blastocyst rate (although there is no difference in the euploidy rate). Trigger-day P is an important factor influencing clinical outcomes in subsequent FET cycles.

Frozen-thawed embryo transfer in modified natural cycles: a retrospective analysis of pregnancy outcomes in ovulatory women with vs. without spontaneous luteinizing hormone surge

Background

Timing of frozen embryo transfer (FET) in natural endometrial preparation cycles is often based on luteinizing hormone (LH) surge. However, some patients do not show spontaneous LH surge despite follicular maturation. The objective of this study was to evaluate the impact of spontaneous LH surge on pregnancy outcomes in modified natural cycles (mNC).

Methods

This retrospective analysis included 1897 FET cycles with modified natural endometrial preparation in normo-ovulatory women between January 1, 2015, to December 31, 2019, at our center: 920 cycles with spontaneous LH surge (≥ 20 IU/L) and 977 without. For cleavage embryos, FET was conducted 4 and 5 days after hCG injection in women with and without LH surge, respectively. For blastocysts, FET was conducted 6 and 7 days after hCG injection in women with and without LH surge, respectively. Multivariate regression was conducted to examine the factors associated with live birth.

Results

Live birth rate was 43.7% in patients with spontaneous LH surge vs. 43.8% in women without LH surge (P = 0.961). The two groups also had similar implantation rate (36.2% vs. 36.7%, P = 0.772), biochemical pregnancy rate (54.8% vs. 55.4%, P = 0.796) and clinical pregnancy rate (50.9% vs. 51.7%, P = 0.721). In multivariate regression, live birth was not associated with LH surge (aOR, 0.947, 95% CI, 0.769, 1.166).

Conclusion

Pregnancy outcomes were similar in mNC-FET in cycles with vs. without spontaneous LH surge if FET timing is adjusted.

Effect of elevated progesterone levels the day before ovulation on pregnancy outcomes in natural cycles of frozen thawed embryo transfer

OBJECTIVE

We aimed to analyze whether elevated progesterone levels on the day before ovulation affected pregnancy outcomes in natural cycles of frozen thawed embryo transfer (NC-FET).

METHODS

A retrospective analysis was conducted in a public university hospital. Data on clinical pregnancy, live birth, ectopic pregnancy, and miscarriage rates were collected, along with other patient data. Patients were divided into two groups according to their progesterone levels the day before ovulation: the progesterone elevation (PE) group (progesterone level >1.0 ng/mL) and the normal progesterone (NP) group (progesterone level ≤1.0 ng/mL). We assessed the effect of elevated progesterone levels in NC-FET by performing multivariate logistic regression analysis.

RESULTS

Overall 1159 women with tubal factor infertility who underwent NC-FET were enrolled, including 666 women who received cleavage-stage embryo transfers and 493 women who received blastocyst embryo transfers. When two cleavage-stage embryos were transferred, the clinical pregnancy rate was significantly higher in the PE than in the NP group following NC-FET (p < .05). After correcting for various confounders, we found that elevated progesterone levels (adjusted odds ratio [OR]: 1.672; 95% confidence interval [CI]: 1.089-2.566, p = .018) improved the clinical pregnancy rate following transfer of two cleavage-stage embryos but did not affect the pregnancy rate when blastocyst-stage embryos were transferred (adjusted OR: 0.856; 95% CI: 0.536-1.369; p = .517).

CONCLUSIONS

The results showed that in patients undergoing cleavage-stage NC-FET, progesterone levels >1.0 ng/mL improved the clinical pregnancy rates. However, the level of progesterone had no effect on the clinical pregnancy rate for patients undergoing blastocyst-stage NC-FET.

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

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

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.

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.

Is there a critical LH level for hCG trigger after the detection of LH surge in modified natural frozen-thawed single blastocyst transfer cycles?

Purpose

There is no consensus yet in the literature on an optimal luteinizing hormone (LH) level for human chorionic gonadotrophin (hCG) trigger timing in patients undergoing frozen-thawed embryo transfer (FET) with modified natural cycles (mNC). The objective of our study was to compare the clinical results of hCG trigger at different LH levels in mNC-FET cases.

Methods

This retrospective study was conducted in Istanbul Memorial Hospital ART and Genetics Center. A total of 1076 cases with 1163 mNC-FET cycles were evaluated. LH levels between the start of LH rise (15 IU/L) and LH peak level (> 40 IU/L) were evaluated. Cycles were analyzed in four groups: group A (n = 287) LH level on the day prior to the day of hCG; groups B, C and D, LH levels on the day of hCG: group B (n = 245) LH 15–24.9; group C (n = 253), LH 25–39.9; group D (n = 383) LH ≥ 40. Cycle outcomes in the four groups were compared.

Results

Subgroup analyses of mNC-FET groups showed that implantation, clinical and ongoing pregnancy rates, and pregnancy losses were not significantly different in patients with different LH levels on the day of hCG trigger.

Conclusion

Our study suggests that hCG can be administered at any time between the start of LH rise (≥ 15 IU/L) and LH peak level (≥ 40 IU/L) without a detrimental effect on clinical outcome.

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.

Maternal and Neonatal Complications After Natural vs. Hormone Replacement Therapy Cycle Regimen for Frozen Single Blastocyst Transfer

Objective: To evaluate the maternal and neonatal complications after frozen-thawed blastocyst transfer cycles utilizing different endometrial preparation regimens.

Design: This is a retrospective cohort study and a secondary analysis of a multicenter, randomized, controlled trial comparing live birth rate after fresh vs. frozen single blastocyst transfer (Frefro-blastocyst).

Setting: Reproductive medicine centers.

Patient(s): A total of 800 women with regular menstrual cycles undergoing their first cycle of in-vitro fertilization after frozen-thawed single blastocyst transfer.

Intervention(s): Endometrium preparation was performed with a natural cycle regimen or hormone replacement therapy (HRT) cycle regimen, at the discretion of local investigators. All pregnancies were followed up until delivery.

Main Outcome Measure(s): Maternal and neonatal complications.

Result(s): 513 infertile patients who underwent natural cycles regimen and 287 who underwent HRT cycles regimen were analyzed. The incidences of maternal and neonatal complications were comparable between the natural cycle and HRT cycle regimen. Regarding the risk of gestational diabetes, gestational hypertension, pre-eclampsia, preterm delivery, small for gestational age and large for gestational age, the HRT cycle was still not a significant risk factor after adjusting for potential confounders. The natural cycle regimen yielded an insignificant higher total live birth rate [59.45 vs. 50.17%, P = 0.001, adjusted odds ratio (AOR) 1.366, 95% confidence interval (CI) 0.975–1.913], clinical pregnancy rate (68.23 vs. 58.89%, P = 0.008, AOR 1.406, 95% CI 0.992–1.991) and ongoing pregnancy rate (62.18 vs. 52.61%, P = 0.008, AOR 1.387, 95% CI 0.988–1.948) than did the HRT cycle regimen. However, compared to natural cycles, HRT cycles were associated with a significantly higher risk of biochemical miscarriage (6.86 vs. 18.18%, P < 0.001, AOR 0.328, 95% CI, 0.176–0.611).

Conclusion(s): The incidence of maternal and neonatal complications in natural cycle and HRT cycle regimens after frozen single blastocyst transfer were comparable. Frozen-thawed single blastocyst transfer in a natural cycle was associated with lower biomedical miscarriage than the use of the HRT cycle.

Clinical Trial Registration Number: Frefro-blastocyst was registered at Chinese Clinical Trial Registry, ChiCTR-IOR-14005405.

Frozen IVF Cycles to Circumvent the Hormonal Storm on Endometrium

Controlled ovarian hyperstimulation (COH) determines an anticipation of endometrial maturation and a premature occurrence of the implantation window, as shown by histological, histochemical, and molecular studies and indirectly by clinical trials. There is growing agreement that in patients hyper-responding to COH and in those undergoing transfer at the blastocyst stage, deferring the transfer in a subsequent frozen cycle could increase pregnancy outcomes. For blastocysts, implantation after a fresh transfer may be limited as the implantation window is already closed while, in hyper-responders to COH, the anticipation magnitude could be more marked thus hampering implantation also for cleavage-stage embryos. Research should focus in depth on pregnancy outcomes and on the most suitable modality to prepare the endometrium for frozen transfers.

Obstetric, Neonatal, and Clinical Outcomes of Day 6 vs. Day 5 Vitrified-Warmed Blastocyst Transfers: Retrospective Cohort Study With Propensity Score Matching

Despite the large number of studies on blastocyst transfers, it is unclear whether day 6 blastocysts have similar pregnancy rates and safety with day 5 blastocysts. Thus, this study aimed to compare the obstetric, neonatal, and clinical outcomes of day 5 and day 6 vitrified blastocyst transfers (VBT). In this retrospective cohort study with propensity score matching, we evaluated 1,313 cycles of VBT performed between January 2014 and December 2015 at the Fertility Center of CHA Gangnam Medical Center. All cycles underwent natural endometrial preparation. We used propensity score matching to compare day 5 and day 6 VBTs in a matched comparison. After propensity score matching, there were 465 cycles of day 5 VBT and 155 cycles of day 6 VBT. Implantation rate (IR), clinical pregnancy rate (CPR), and live birth rate (LBR) were significantly lower in day 6 VBTs (44.2 vs. 53.1%, p = 0.023; 48.4 vs. 60.4%, p = 0.009; 33.5 vs. 51.8%, p < 0.001). Miscarriage rate was significantly higher in day 6 VBTs (29.3 vs. 10.7%, p < 0.001). Rate of multiple gestations was similar between the two groups (29.3 vs. 30.2%, p = 0.816). Assessing 241 and 52 babies from day 5 and day 6 VBTs, no differences were found in neonatal outcomes including rates of low birth weight, preterm birth, and congenital malformations. In propensity score-matched analysis, obstetric, and neonatal outcomes between day 5 and day 6 VBTs were similar so that day 6 VBTs are as safe as day 5 VBTs. IR, CPR, and LBR were are all significantly lower in day 6 VBTs. Therefore, if there are no differences in the morphological grade between day 5 and day 6 blastocysts, transfer of day 5 vitrified blastocysts should be considered first.

Progesterone elevation on the day of hCG trigger has detrimental effect on live birth rate in low and intermediate ovarian responders, but not in high responders

Progesterone elevation (PE) on the day of hCG trigger is associated with decreased pregnancy outcome in fresh cycles. Evidence for this comes from overall patient estimates that mostly ignore different ovarian responses. To compare the impacts of PE on the day of hCG trigger on live birth rates (LBs) in low, intermediate and high ovarian responders and to explore the cut-off value for PE in different populations according to the ovarian response, we retrospectively analyzed a total of 2,351 patients receiving fresh assisted reproduction technology (ART) transfer cycles with GnRH agonist using a long or short protocol. Trend and multivariate logistic regression analyses were performed to identify the cutoff values of PE and to evaluate the effects of PE on LB rates (LBRs) in different ovarian responders. The study found that PE has a detrimental effect on LBRs in low to intermediate ovarian responders rather than in high responders. The cut-off values for PE were 1.0 ng/mL and 2.0 ng/mL for low and intermediate ovarian responders, respectively. The different associations between PE and LBRs according to ovarian response could more accurately predict the prognosis of the IVF cycle and could be used to optimize the treatment of patients undergoing In Vitro Fertilization (IVF)/ Intracytoplasmic Sperm Injection (ICSI).

High responders are not exempt from detrimental effects of prematurely rising progesterone levels in fresh embryo transfer cycles

RESEARCH QUESTION

Are high-responder IVF patients protected from the deleterious effect of prematurely elevated serum progesterone level on the probability of pregnancy?

DESIGN

In this retrospective cohort study, 2971 autologous fresh embryo transfer IVF cycles with gonadotrophin-releasing hormone agonist long protocol were analysed to investigate whether the detrimental effect of prematurely rising progesterone levels on clinical pregnancy rate (CPR) varies depending on the magnitude of ovarian response. Nine different evenly spaced intervals were constructed for serum progesterone level on the human chorionic gonadotrophin day (<0.5/0.5-0.9/1-1.4/1.5-1.9/2-2.4/2.5-2.9/3-3.4/3.5-3.9/>4 ng/ml). Then, IVF cycles in each of these intervals were further divided into low (≤3 oocytes), normal (4-15 oocytes) and high responders (≥16 oocytes).

RESULTS

The progressive rise of serum progesterone from the <0.5 to the >4 ng/ml interval caused a gradual and continuous decline in the CPR of all three types of ovarian response. The absolute difference in the CPR between the lowest and the highest progesterone groups was not related to the magnitude of ovarian response (-26.6%, -37.7% and -40.7% for the low, normal and high responders, respectively). On multivariate logistic regression analysis, the detrimental effect of progesterone started at 1.5-1.9 ng/ml, 3.0-3.4 ng/ml and 4.0-4.4 ng/ml intervals for the low, normal and high responders, respectively.

CONCLUSION

High responders are not exempt from the detrimental effects of prematurely rising serum progesterone levels but the threshold interval where the detrimental effect begins is higher in the high responders compared with the low and normal responders.

The curious case of premature luteinization

PURPOSE

Premature luteinization (PL) affects 12.3-46.7% of fresh in vitro fertilization cycles, and there is accumulating evidence confirming its negative effect on success rates. However, despite its clinical significance, PL is poorly understood and defined. This narrative review aims to provide a fresh look at the phenomenon of PL by summarizing the existing evidence and re-evaluating fundamental issues.

METHODS

A thorough electronic search was conducted covering the period from 1978 until January 2018 in PubMed, Embase, and Medline databases, and references of relevant studies were cross-checked. Meeting proceedings of the European Society of Human Reproduction and Embryology and the American Society for Reproductive Medicine were also hand searched.

RESULTS

In the curious case of PL, one should go back to the beginning and re-consider every step of the way. The pathogenesis, definition, measurement methods, clinical implications, and management strategies are discussed in detail, highlighting controversies and offering "food for thought" for future directions.

CONCLUSIONS

Authors need to speak the same language when studying PL in order to facilitate comparisons. The terminology, progesterone cut-off, measurement methods and days of measurement should be standardized and globally accepted; otherwise, there can be no scientific dialog. Future research should focus on specific patient profiles that may require a tailored approach. Progesterone measurements throughout the follicular phase possibly depict the progesterone exposure better than an isolated measurement on the day of hCG. Adequately powered randomized controlled trials should confirm which the best prevention and management plan of PL is, before introducing any strategy into clinical practice.

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

Progesterone elevation (PE) during the late follicular phase of controlled ovarian stimulation in fresh embryo transfer in vitro fertilization (IVF)/intracytoplasmic sperm injection cycles has been claimed to be associated with decreased pregnancy rates. However, the evidence is not unequivocal, and clinicians still have questions about the clinical validity of measuring P levels during the follicular phase of stimulated cycles. We reviewed the existing literature aimed at answering four relevant clinical questions, namely (i) Is gonadotropin type associated with PE during the follicular phase of stimulated cycles? (ii) Is PE on the day of human chorionic gonadotropin (hCG) associated with negative fresh embryo transfer IVF/intracytoplasmic sperm injection (ICSI) cycles outcomes in all patient subgroups? (iii) Which P thresholds are best to identify patients at risk of implantation failure due to PE in a fresh embryo transfer? and (iv) Should a freeze all policy be adopted in all the cycles with PE on the day of hCG? The existing evidence indicates that late follicular phase progesterone rise in gonadotropin releasing analog cycles is mainly caused by the supraphysiological stimulation of granulosa cells with exogenous follicle-stimulating hormone. Yet, the type of gonadotropin used for stimulation seems to play no significant role on progesterone levels at the end of stimulation. Furthermore, PE is not a universal phenomenon with evidence indicating that its detrimental consequences on pregnancy outcomes do not affect all patient populations equally. Patients with high ovarian response to control ovarian stimulation are more prone to exhibit PE at the late follicular phase. However, in studies showing an overall detrimental effect of PE on pregnancy rates, the adverse effect of PE on endometrial receptivity seems to be offset, at least in part, by the availability of good quality embryo for transfer in women with a high ovarian response. Given the limitations of the currently available assays to measure progesterone at low ranges, caution should be applied to adopt specific cutoff values above which the effect of progesterone rise could be considered detrimental and to recommend "freeze-all" based solely on pre-defined cutoff points.

Frozen embryo transfer: a review on the optimal endometrial preparation and timing

STUDY QUESTION

What is the optimal endometrial preparation protocol for a frozen embryo transfer (FET)?

SUMMARY ANSWER

Although the optimal endometrial preparation protocol for FET needs further research and is yet to be determined, we propose a standardized timing strategy based on the current available evidence which could assist in the harmonization and comparability of clinic practice and future trials.

WHAT IS KNOWN ALREADY

Amid a continuous increase in the number of FET cycles, determining the optimal endometrial preparation protocol has become paramount to maximize ART success. In current daily practice, different FET preparation methods and timing strategies are used.

STUDY DESIGN, SIZE, DURATION

This is a review of the current literature on FET preparation methods, with special attention to the timing of the embryo transfer.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Literature on the topic was retrieved in PubMed and references from relevant articles were investigated until June 2017.

MAIN RESULTS AND THE ROLE OF CHANCE

The number of high quality randomized controlled trials (RCTs) is scarce and, hence, the evidence for the best protocol for FET is poor. Future research should compare both the pregnancy and neonatal outcomes between HRT and true natural cycle (NC) FET. In terms of embryo transfer timing, we propose to start progesterone intake on the theoretical day of oocyte retrieval in HRT and to perform blastocyst transfer at hCG + 7 or LH + 6 in modified or true NC, respectively.

LIMITATIONS REASONS FOR CAUTION

As only a few high quality RCTs on the optimal preparation for FET are available in the existing literature, no definitive conclusion for benefit of one protocol over the other can be drawn so far.

WIDER IMPLICATIONS OF THE FINDINGS

Caution when using HRT for FET is warranted since the rate of early pregnancy loss is alarmingly high in some reports.

STUDY FUNDING/COMPETING INTEREST(S)

S.M. is funded by the Research Fund of Flanders (FWO). H.T. and C.B. report grants from Merck, Goodlife, Besins and Abbott during the conduct of the study.

TRIAL REGISTRATION NUMBER

Not applicable.

Outcomes and Recommendations of an Indian Expert Panel for Improved Practice in Controlled Ovarian Stimulation for Assisted Reproductive Technology

Purpose. To improve success of in vitro fertilization (IVF), assisted reproductive technology (ART) experts addressed four questions. What is optimum oocytes number leading to highest live birth rate (LBR)? Are cohort size and embryo quality correlated? Does gonadotropin type affect oocyte yield? Should “freeze-all” policy be adopted in cycles with progesterone >1.5 ng/mL on day of human chorionic gonadotropin (hCG) administration? Methods. Electronic database search included ten studies on which panel gave opinions for improving current practice in controlled ovarian stimulation for ART. Results. Strong association existed between retrieved oocytes number (RON) and LBRs. RON impacted likelihood of ovarian hyperstimulation syndrome (OHSS). Embryo euploidy decreased with age, not with cohort size. Progesterone > 1.5 ng/dL did not impair cycle outcomes in patients with high cohorts and showed disparate results on day of hCG administration. Conclusions. Ovarian stimulation should be designed to retrieve 10–15 oocytes/treatment. Accurate dosage, gonadotropin type, should be selected as per prediction markers of ovarian response. Gonadotropin-releasing hormone (GnRH) antagonist based protocols are advised to avoid OHSS. Cumulative pregnancy rate was most relevant pregnancy endpoint in ART. Cycles with serum progesterone ≥1.5 ng/dL on day of hCG administration should not adopt “freeze-all” policy. Further research is needed due to lack of data availability on progesterone threshold or index.

A randomized controlled, non-inferiority trial of modified natural versus artificial cycle for cryo-thawed embryo transfer

STUDY QUESTION

Are live birth rates (LBRs) after artificial cycle frozen-thawed embryo transfer (AC-FET) non-inferior to LBRs after modified natural cycle frozen-thawed embryo transfer (mNC-FET)?

SUMMARY ANSWER

AC-FET is non-inferior to mNC-FET with regard to LBRs, clinical and ongoing pregnancy rates (OPRs) but AC-FET does result in higher cancellation rates.

WHAT IS ALREADY KNOWN

Pooling prior retrospective studies of AC-FET and mNC-FET results in comparable pregnancy and LBRs. However, these results have not yet been confirmed by a prospective randomized trial.

STUDY DESIGN, SIZE AND DURATION

In this non-inferiority prospective randomized controlled trial (acronym 'ANTARCTICA' trial), conducted from February 2009 to April 2014, 1032 patients were included of which 959 were available for analysis. The primary outcome of the study was live birth. Secondary outcomes were clinical and ongoing pregnancy, cycle cancellation and endometrium thickness. A cost-efficiency analysis was performed.

PARTICIPANT/MATERIALS, SETTING, METHODS

This study was conducted in both secondary and tertiary fertility centres in the Netherlands. Patients included in this study had to be 18-40 years old, had to have a regular menstruation cycle between 26 and 35 days and frozen-thawed embryos to be transferred had to derive from one of the first three IVF or IVF-ICSI treatment cycles. Patients with a uterine anomaly, a contraindication for one of the prescribed medications in this study or patients undergoing a donor gamete procedure were excluded from participation. Patients were randomized based on a 1:1 allocation to either one cycle of mNC-FET or AC-FET. All embryos were cryopreserved using a slow-freeze technique.

MAIN RESULTS AND THE ROLE OF CHANCE

LBR after mNC-FET was 11.5% (57/495) versus 8.8% in AC-FET (41/464) resulting in an absolute difference in LBR of -0.027 in favour of mNC-FET (95% confidence interval (CI) -0.065-0.012; P = 0.171). Clinical pregnancy occurred in 94/495 (19.0%) patients in mNC-FET versus 75/464 (16.0%) patients in AC-FET (odds ratio (OR) 0.8, 95% CI 0.6-1.1, P = 0.25). 57/495 (11.5%) mNC-FET resulted in ongoing pregnancy versus 45/464 (9.6%) AC-FET (OR 0.7, 95% CI 0.5-1.1, P = 0.15). χ(2) test confirmed the lack of superiority. Significantly more cycles were cancelled in AC-FET (124/464 versus 101/495, OR 1.4, 95% CI 1.1-1.9, P = 0.02). The costs of each of the endometrial preparation methods were comparable (€617.50 per cycle in NC-FET versus €625.73 per cycle in AC-FET, P = 0.54).

LIMITATIONS, REASONS FOR CAUTION

The minimum of 1150 patients required for adequate statistical power was not achieved. Moreover, LBRs were lower than anticipated in the sample size calculation.

WIDER IMPLICATIONS OF THE FINDINGS

LBRs after AC-FET were not inferior to those achieved by mNC-FET. No significant differences in clinical and OPR were observed. The costs of both treatment approaches were comparable.

STUDY FUNDING/COMPETING INTERESTS

An educational grant was received during the conduct of this study. Merck Sharpe Dohme had no influence on the design, execution and analyses of this study. E.R.G. received an education grant by Merck Sharpe Dohme (MSD) during the conduct of the present study. B.J.C. reports grants from MSD during the conduct of the study. A.H. reports grants from MSD and Ferring BV the Netherlands and personal fees from MSD. Grants from ZonMW, the Dutch Organization for Health Research and Development. J.S.E.L. reports grants from Ferring, MSD, Organon, Merck Serono and Schering-Plough during the conduct of the study. F.J.M.B. receives monetary compensation as member of the external advisory board for Merck Serono, consultancy work for Gedeon Richter, educational activities for Ferring BV, research cooperation with Ansh Labs and a strategic cooperation with Roche on automated anti Mullerian hormone assay development. N.S.M. reports receiving monetary compensations for external advisory and speaking work for Ferring BV, MSD, Anecova and Merck Serono during the conduct of the study. All reported competing interests are outside the submitted work. No other relationships or activities that could appear to have influenced the submitted work.

TRIAL REGISTRATION NUMBER

Netherlands trial register, number NTR 1586.

TRIAL REGISTRATION DATE

13 January 2009.

FIRST PATIENT INCLUDED

20 April 2009.

The effect of a high progesterone concentration before oocyte retrieval on the peri-implantation endometrium

In this single-centre, prospective cohort study, the effect of high progesterone level before oocyte retrieval on endometrial morphology and uterine natural killer cell (uKN) count in the peri-implantation period was investigated. A total of 106 women undergoing IVF treatment who did not proceed to fresh embryo transfer were included. Endometrial samples were obtained 7 days after HCG administration. Multiple regression analysis was used to identify factors affecting the results of histological staging and uNK cell count. Progesterone level on the day after HCG administration was the only significant variable associated with the results of histological staging (P = 0.004). Endometrial development in women with high progesterone level was significantly (P < 0.001) more advanced than that of women with normal progesterone; progesterone level on the day of HCG administration was the only significant variable associated with uNK cell count. The median (range) of uNK cell count of 9.6% (2.3-21.6%) in women with high progesterone was significantly (P < 0.001) higher than the median (range) of uNK cell count of 5.7% (1.4-18.7%) in women with normal progesterone. High progesterone level before oocyte retrieval was correlated with advancement in endometrial development as well as increased uNK cell count.

Progesterone elevation on the day of human chorionic gonadotropin administration adversely affects the outcome of IVF with transferred embryos at different developmental stages

BACKGROUND

The effect of progesterone elevation (PE) on the day of human chorionic gonadotropin (hCG) administration on the pregnancy outcomes of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles is a matter of ongoing debate. The replacement of cleavage-stage embryos with blastocyst-stage embryos for transfer was proposed to avoid the possible impairment of PE in fresh cycles. This study aimed to assess the association between PE on the day of human chorionic gonadotropin (hCG) administration and clinical pregnancy rates (CPRs) in IVF/ICSI cycles with embryos transferred at different developmental stages (cleavage and blastocyst). Moreover, a secondary aim was to determine the thresholds at which PE has a detrimental effect on CPRs.

METHODS

This single-center retrospective cohort study included more than 10,000 patients undergoing day 3 cleavage-stage embryo transfer (ET) and 1146 patients undergoing day 5 blastocyst-stage embryo transfer (ET) using gonadotropin and GnRH agonist for controlled ovarian stimulation.

RESULTS

Serum PE was inversely associated with CPRs in both cleavage- and blastocyst-stage ET cycles. In the day 3 ET cycles, CPRs (progesterone levels < 0.5 ng/ml, 49.2 %) significantly declined when the progesterone concentration reached 1.0 ng/ml (45.5 %) and decreased further when the progesterone concentration increased to 1.5 ng/ml (36.2 %). In the day 5 blastocyst-stage ET cycles, patients with serum progesterone levels ≥1.75 ng/ml had significantly lower CPRs (31.3 % VS. 41.4 %, p < 0.001) compared to patients with serum progesterone levels <1.75 ng/ml. The negative association of PE with CPRs was noted in both ET groups, even after adjusting for confounders. Furthermore, the developmental stage of the transferred embryos was not linked to the effect of PE on CPRs because the interaction between the developmental stage of the transferred embryos and PE was not significant.

CONCLUSIONS

PE on the day of hCG administration is associated with decreased CPRs in GnRH agonist IVF/intracytoplasmic sperm injection (ICSI) cycles regardless of the developmental stage of the transferred embryos (cleavage versus blastocyst stage).