Intra-individual variability of serum progesterone levels on the day of frozen blastocyst transfer in hormonal replacement therapy cycles.

STUDY QUESTION: Is there a significant intra-individual variability of serum progesterone levels on the day of single blastocyst Hormone Replacement Therapy-Frozen Embryo Transfer (HRT-FET) between two consecutive cycles? SUMMARY ANSWER: No significant intra-individual variability of serum progesterone (P) levels was noted between two consecutive HRT-FET cycles. WHAT IS KNOWN ALREADY: In HRT-FET cycles, a minimum P level on the day of embryo transfer is necessary to optimise reproductive outcomes. In a previous study by our team, a threshold of 9.8 ng/ml serum P was identified as significantly associated with the live birth rates in single autologous blastocyst transfers under HRT using micronized vaginal progesterone (MVP). Such patients may benefit from an intensive luteal phase support (LPS) using other routes of P administration in addition to MVP. A crucial question in the way towards individualising LPS is whether serum P measurements are reproducible for a given patient in consecutive HRT-FET cycles, using the same LPS. STUDY DESIGN, SIZE, DURATION: We conducted an observational cohort study at the university-based reproductive medicine centre of our institution focusing on women who underwent at least two consecutive single autologous blastocyst HRT-FET cycles between January 2019 and March 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients undergoing two consecutive single autologous blastocyst HRT-FET cycles using exogenous oestradiol and vaginal micronized progesterone for endometrial preparation were included. Serum progesterone levels were measured on the morning of the Frozen Embryo Transfer (FET), by a single laboratory. The two measurements of progesterone levels performed on the day of the first (FET1) and the second FET (FET2) were compared to evaluate the intra-individual variability of serum P levels. Paired statistical analyses were performed, as appropriate. MAIN RESULTS AND THE ROLE OF CHANCE: Two hundred and sixty-four patients undergoing two consecutive single autologous blastocyst HRT-FET were included. The mean age of the included women was 35.0 ± 4.2 years. No significant intra-individual variability was observed between FET1 and FET2 (mean progesterone level after FET1: 13.4 ± 5.1 ng/ml vs after FET2: 13.9 ± 5.0; P = 0.08). The characteristics of the embryo transfers were similar between the first and the second FET. Forty-nine patients (18.6%) had discordant progesterone levels (defined as one progesterone measurement > and one ≤ to the threshold of 9.8 ng/ml) between FET1 and FET2. There were 37/264 women (14.0%) who had high intra-individual variability (defined as a difference in serum progesterone values >75th percentile (6.0 ng/ml)) between FET1 and FET2. No specific clinical parameter was associated with a high intra-individual variability nor a discordant P measurement. LIMITATIONS, REASONS FOR CAUTION: This study is limited by its retrospective design. Moreover, only women undergoing autologous blastocyst HRT-FET with MVP were included, thereby limiting the extrapolation of the study findings to other routes of P administration and other kinds of endometrial preparation for FET. WIDER IMPLICATIONS OF THE FINDINGS: No significant intra-individual variability was noted. The serum progesterone level appeared to be reproducible in >80% of cases. These findings suggest that the serum progesterone level measured on the day of the first transfer can be used to individualize luteal phase support in subsequent cycles. STUDY FUNDING/COMPETING INTEREST(S): No funding or competing interests. TRIAL REGISTRATION NUMBER: N/A.

Luteal phase support using micronized vaginal progesterone as pessaries or capsules in artificial cycles: is there any difference?

RESEARCH QUESTION: Is there a difference between the proportion of patients with serum progesterone <8.8 ng/ml on the day of embryo transfer when micronized vaginal progesterone (MVP) for luteal phase support (LPS) is given as pessaries versus capsules? DESIGN: This retrospective, matched-cohort, single-centre study compared pessaries (Cyclogest) versus capsules (Utrogestan, Progeffik) for LPS in hormone replacement treatment-embryo transfer (HRT-ET) cycles. Patients under 50 years old with a triple-layer endometrial thickness of ≥6.5 mm underwent transfer of one or two blastocysts. Serum progesterone concentrations were measured on the day of transfer; patients with concentrations <8.8 ng/ml received a single 'rescue' dose of additional progesterone by subcutaneous injection. RESULTS: In total 2665 HRT-ET cycles were analysed; 663 (24.9%) used pessaries for LPS and 2002 (75.1%) used capsules. Mean serum progesterone concentrations with standard deviations on the day of embryo transfer were significantly higher in the group using MVP pessaries compared with those using capsules (14.5 ± 5.1 versus 13.0 ± 4.8 ng/ml; P = 0.000). The percentage of participants with suboptimal serum progesterone concentrations on the day of embryo transfer (<8.8 ng/ml) was significantly lower in the pessary group than the capsule group (10.3%, 95% confidence interval [CI] 7.9-12.6% versus 17.9%, 95% CI 16.2-19.6%; adjusted odds ratio 0.426, 95% CI 0.290-0.625; P = 0.000). No differences in pregnancy outcome were observed between the groups. CONCLUSIONS: Using MVP pessaries rather than capsules for LPS resulted in significantly fewer patients having suboptimal serum progesterone concentrations on the day of embryo transfer. Consequently, almost 50% fewer patients in the pessary group needed rescue treatment.

The combination of dydrogesterone and micronized vaginal progesterone can render serum progesterone level measurements on the day of embryo transfer and rescue attempts unnecessary in an HRT FET cycle.

PURPOSE: To evaluate the role of serum progesterone (P4) on the day of embryo transfer (ET) when dydrogesterone (DYD) and micronized vaginal progesterone (MVP) are combined as luteal phase support (LPS) in a hormone replacement therapy (HRT) frozen ET (FET) cycles. METHODS: Retrospective study, including single euploid HRT FET cycles with DYD and MVP as LPS and P4 measurement on ET day. Initially, patients with P4 levels < 10 ng/ml increased MVP to 400 mg/day; this "rescue" was abandoned later. RESULTS: 560 cycles of 507 couples were included. In 275 women, serum P4 level was < 10 ng/ml on the ET day. Among those with low P4 levels, MVP dose remained unchanged in 65 women (11.6%) and was increased in 210 women (37.5%). Women with P4 levels ≥ 10 ng/ml continued LPS without modification. Overall pregnancy rates in these groups were 61.5% (40/65), 54.8% (115/210), and 48.4% (138/285), respectively (p = n.s.). Association of serum P4 levels with ongoing pregnancy rates was analyzed in women without any additional MVP regardless of serum P4 levels (n = 350); multivariable analysis (adjusted for age, BMI, embryo quality (EQ)) did not show a significant association of serum P4 levels with OPR (OR 0.96, 95% CI 0.90-1.02; p = 0.185). Using inverse probability treatment weights, regression analysis in the weighted sample showed no significant association between P4 treatment groups and OP. Compared to fair EQ, the transfer of good EQ increased (OR 1.61, 95% CI 1.22-2.15; p = 0.001) and the transfer of a poor EQ decreased the odds of OP (OR 0.73, 95% CI 0.55-0.97; p = 0.029). CONCLUSION: In HRT FET cycle, using LPS with 300 mg/day MVP and 30 mg/day DYD, it appears that serum P4 measurement and increase of MVP in patients with P4 < 10 ng/ml are not necessary.

Comparison between oral dydrogesterone versus micronized vaginal progesterone gel in clinical outcome within the first HRT-FET cycle: a retrospective analysis.

OBJECTIVE: The purpose of this study is to compare the clinical efficacy of oral dydrogesterone and micronized vaginal progesterone (MVP) gel during the first HRT-FET cycle. METHODS: A retrospective cohort study based on a total of 344 women undergoing their first HRT-FET cycles without Gonadotropin-Releasing Hormone agonist (GnRH-a) pretreatment was conducted. All the cycles were allocated to two groups in the reproductive medical center at the University of Hong Kong-Shenzhen Hospital. One group (n = 193) received oral dydrogesterone 30 mg/d before embryo transfer, while the other group (n = 151) received MVP gel 180 mg/d. RESULTS: The demographics and baseline characteristics of two groups were comparable. We found no statistically significant difference in live birth rate (24.35% vs. 31.13%, P = 0.16), clinical pregnancy rate (34.72% vs. 36.42%, P = 0.74), embryo implantation rate (25.09% vs. 28.36%, P = 0.43), positive pregnancy rate (42.49% vs 38.41%, P = 0.45), miscarriage rate (9.33% vs 3.97%, P = 0.05), or ectopic pregnancy rate (0.52% vs. 0.66%, P = 0.86) between the oral dydrogesterone group and MVP gel group. In the multivariate logistic regression analysis for covariates, medication used for luteal support was not associated with live birth rate (OR = 0.73, 95% CI: 0.32-1.57, P = 0.45). And the different luteal support medication did not have a significant positive association with the live birth rate in the cycles with day 2 embryo transferred (OR = 1.39, 95% CI:0.66-2.39, P = 0.39) and blastocyst transferred (OR = 1.31 95% CI:0.64-2.69, P = 0.46). CONCLUSION: 30 mg/d oral dydrogesterone and 180 mg/d MVP gel revealed similar reproductive outcomes in HRT-FET cycles in the study.

Clinical factors associated with low serum progesterone levels on the day of frozen blastocyst transfer in hormonal replacement therapy cycles.

STUDY QUESTION: Which factors are associated with low serum progesterone (P) levels on the day of frozen embryo transfer (FET), in HRT cycles? SUMMARY ANSWER: BMI, parity and non-European geographic origin are factors associated with low serum P levels on the day of FET in HRT cycles. WHAT IS KNOWN ALREADY: The detrimental impact of low serum P concentrations on HRT-FET outcomes is commonly recognized. However, the factors accounting for P level disparities among patients receiving the same luteal phase support treatment remain to be elucidated, to help clinicians predicting which subgroups of patients would benefit from a tailored P supplementation. STUDY DESIGN, SIZE, DURATION: Observational cohort study with 915 patients undergoing HRT-FET at a tertiary care university hospital, between January 2019 and March 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients undergoing single autologous blastocyst FET under HRT using exogenous estradiol and vaginal micronized progesterone for endometrial preparation. Women were only included once during the study period. The serum progesterone level was measured in the morning of the FET, in a single laboratory. Independent factors associated with low serum P levels (defined as ≤9.8 ng/ml, according to a previous published study) were analyzed using univariate and multivariate logistic regression models. MAIN RESULTS AND THE ROLE OF CHANCE: Two hundred and twenty-six patients (24.7%) had a low serum P level, on the day of the FET. Patients with a serum P level ≤9.8 ng/ml had a lower live birth rate (26.1% vs 33.2%, P = 0.045) and a higher rate of early miscarriage (35.2% vs 21.5%, P = 0.008). Univariate analysis showed that BMI (P < 0.001), parity (P = 0.001), non-European geographic origin (P = 0.001), the duration of infertility (P = 0.018) and the use of oral estradiol for endometrial preparation (P = 0.009) were significantly associated with low serum P levels. Moreover, the proportion of active smokers was significantly lower in the 'low P concentrations' group (P = 0.002). After multivariate analysis, BMI (odds ratio (OR) 1.06 95% CI (1.02-1.11), P = 0.002), parity (OR 1.32 95% CI (1.04-1.66), P = 0.022), non-European geographic origin (OR 1.70 95% CI (1.21-2.39), P = 0.002) and active smoking (OR 0.43 95% CI (0.22-0.87), P = 0.018) remained independent factors associated with serum P levels ≤9.8 ng/ml. LIMITATIONS, REASONS FOR CAUTION: The main limitation of this study is its observational design, leading to a risk of selection and confusion bias that cannot be ruled out, although a multivariable analysis was performed to minimize this. WIDER IMPLICATIONS OF THE FINDINGS: Extrapolation of our results to other laboratories, or other routes and/or doses of administering progesterone also needs to be validated. There is urgent need for future research on clinical factors affecting P concentrations and the underlying pathophysiological mechanisms, to help clinicians in predicting which subgroups of patients would benefit from individualized luteal phase support. STUDY FUNDING/COMPETING INTEREST(S): No funding/no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Low serum progesterone affects live birth rate in cryopreserved blastocyst transfer cycles using hormone replacement therapy.

RESEARCH QUESTION: Does serum progesterone concentration on the day of vitrified-warmed embryo transfer affect live birth rate (LBR) with hormonal replacement therapy (HRT) cycles? DESIGN: Observational cohort study of patients (n = 915) undergoing single autologous vitrified-warmed blastocyst transfer under HRT using vaginal micronized progesterone. Women were included once, between January 2019 and March 2020. Serum progesterone concentration was measured by a single laboratory on the morning of embryo transfer. The primary end point was LBR. Univariate and multivariate logistic regression models were used for statistical analyses. RESULTS: Median (25th-75th percentile) serum progesterone concentration on the day of embryo transfer was 12.5 ng/ml (9.8-15.3). The LBR was 31.5% (288/915) in the overall population. No significant differences were found in implantation rates (40.7% versus 44.9%); LBR was significantly lower in women with a progesterone concentration ≤25th percentile (≤9.8 ng/ml) (26.1% versus 33.2%, P = 0.045) versus women with a progesterone concentration >25th percentile. This correlated with a significantly higher early miscarriage rate (35.9% versus 21.6%, P = 0.005). After adjusting for potential confounding factors in multivariate analysis, low serum progesterone levels (≤9.8 ng/ml) remained significantly associated with lower LBR (OR 0.68 95% CI 0.48 to 0.97). CONCLUSION: A minimum serum progesterone concentration is needed to optimize reproductive outcomes in HRT cycles with single autologous vitrified-warmed blastocyst transfer. Whether modifications of progesterone administration routes, dosage, or both, can improve pregnancy rates needs further study so that treatment of patients undergoing HRT cycles can be further individualized.

A Phase III randomized controlled trial of oral dydrogesterone versus intravaginal progesterone gel for luteal phase support in in vitro fertilization (Lotus II): results from the Chinese mainland subpopulation.

Lotus II, a randomized, open-label, multicenter, international study compared the efficacy and safety of oral dydrogesterone versus micronized vaginal progesterone (MVP) gel for luteal support in IVF. A prespecified subgroup analysis was performed on 239 Chinese mainland subjects from the overall study population (n = 1034), who were randomized to oral dydrogesterone 30 mg or 8% MVP gel 90 mg daily from the day of oocyte retrieval until 12 weeks of gestation. The aim was to demonstrate non-inferiority of oral dydrogesterone to MVP gel, assessed by the presence of a fetal heartbeat at 12 weeks of gestation. In the Chinese mainland subpopulation, there was a numerical difference of 9.4% in favor of oral dydrogesterone, with ongoing pregnancy rates at 12 weeks of gestation of 61.4% and 51.9% in the oral dydrogesterone and MVP gel groups, respectively (adjusted difference, 9.4%; 95% CI: -3.4 to 22.1); in the overall population, these were 38.7% and 35%, respectively (adjusted difference, 3.7%; 95% CI: -2.3 to 9.7). In both the Chinese mainland subpopulation and the overall population, dydrogesterone had similar efficacy and safety to MVP gel. With convenient oral administration, dydrogesterone has potential to transform luteal support treatment.

A Phase III randomized controlled trial comparing the efficacy, safety and tolerability of oral dydrogesterone versus micronized vaginal progesterone for luteal support in in vitro fertilization.

STUDY QUESTION: Is oral dydrogesterone 30 mg daily (10 mg three times daily [TID]) non-inferior to micronized vaginal progesterone (MVP) 600 mg daily (200 mg TID) for luteal support in in vitro fertilization (IVF), assessed by the presence of fetal heartbeats determined by transvaginal ultrasound at 12 weeks of gestation? SUMMARY ANSWER: Non-inferiority of oral dydrogesterone versus MVP was demonstrated at 12 weeks of gestation, with a difference in pregnancy rate and an associated confidence interval (CI) that were both within the non-inferiority margin. WHAT IS KNOWN ALREADY: MVP is routinely used in most clinics for luteal support in IVF, but it is associated with side effects, such as vaginal irritation and discharge, as well as poor patient acceptance. Dydrogesterone may be an alternative treatment due to its patient-friendly oral administration. STUDY DESIGN, SIZE, DURATION: Lotus I was an international Phase III randomized controlled trial, performed across 38 sites, from August 2013 to March 2016. Subjects were premenopausal women (>18 to <42 years of age; body mass index (BMI) ≥18 to ≤30 kg/m2) with a documented history of infertility who were planning to undergo IVF. A centralized electronic system was used for randomization, and the study investigators, sponsor's study team, and subjects remained blinded throughout the study. PARTICIPANTS/MATERIALS, SETTING, METHODS: In total, 1031 subjects were randomized to receive either oral dydrogesterone (n = 520) or MVP (n = 511). Luteal support was started on the day of oocyte retrieval and continued until 12 weeks of gestation (Week 10), if a positive pregnancy test was obtained at 2 weeks after embryo transfer. MAIN RESULTS AND THE ROLE OF CHANCE: In the full analysis set (FAS), 497 and 477 subjects in the oral dydrogesterone and MVP groups, respectively, had an embryo transfer. Non-inferiority of oral dydrogesterone was demonstrated, with pregnancy rates at 12 weeks of gestation of 37.6% and 33.1% in the oral dydrogesterone and MVP treatment groups, respectively (difference 4.7%; 95% CI: -1.2-10.6%). Live birth rates of 34.6% (172 mothers with 213 newborns) and 29.8% (142 mothers with 158 newborns) were obtained in the dydrogesterone and MVP groups, respectively (difference 4.9%; 95% CI: -0.8-10.7%). Oral dydrogesterone was well tolerated and had a similar safety profile to MVP. LIMITATIONS, REASONS FOR CAUTION: The analysis of the results was powered to consider the clinical pregnancy rate, but the live birth rate may be of greater clinical interest. Conclusions relating to the differences between treatments in live birth rate, observed in this study, should therefore be made with caution. WIDER IMPLICATIONS OF THE FINDINGS: Oral dydrogesterone may replace MVP as the standard of care for luteal phase support in IVF, owing to the oral route being more patient-friendly than intravaginal administration, as well as it being a well tolerated and efficacious treatment. STUDY FUNDING/COMPETING INTEREST(S): Sponsored and supported by Abbott Established Pharmaceuticals Division. H.T.'s institution has received grants from Merck, MSD, Goodlife, Cook, Roche, Besins, Ferring and Mithra (now Allergan) and H.T. has received consultancy fees from Finox, Ferring, Abbott, ObsEva and Ovascience. G.S. has nothing to disclose. E.K. is an employee of Abbott GmbH. G.G. has received investigator fees from Abbott during the conduct of the study; outside of this submitted work, G.G. has received personal fees and non-financial support from MSD, Ferring, Merck-Serono, Finox, TEVA, Glycotope, as well as personal fees from VitroLife, NMC Healthcare LLC, ReprodWissen LLC and ZIVA LLC. TRIAL REGISTRATION NUMBER: NCT01850030 (clinicaltrials.gov). TRIAL REGISTRATION DATE: 19 April 2013. DATE OF FIRST PATIENT'S ENROLLMENT: 23 August 2013.

Assessment of sub-endometrial blood flow parameters following dydrogesterone and micronized vaginal progesterone administration in women with idiopathic recurrent miscarriage: a pilot study.

AIM: To evaluate differences in uteroplacental blood flow and pregnancy outcome in women with idiopathic recurrent spontaneous miscarriage (IRSM) following administration of micronized vaginal progesterone and oral dydrogesterone. METHODS: One hundred and thirty-three women (aged 23-40 years) who had had early miscarriages and spontaneous conception participated. Oral dydrogesterone (group A, n = 51) and micronized vaginal progesterone (group B, n = 50) were administrated for luteal support and compared. Pregnant women without history of recurrent miscarriage served as controls (group C, n = 32). The outcome measures consisted of endometrial blood flow parameters by Doppler indices and ongoing pregnancy rate. RESULTS: Before progesterone supplementation, resistivity index (RI) and pulsatility index (PI) were found to be significantly higher in groups A and B as compared to controls. Although statistically not significant, end diastolic velocity (EDV) and systolic/diastolic (S/D) ratio was found to be superior in controls than IRSM women. Peak systolic velocity (PSV) was comparable between IRSM and non-IRSM groups. Following progesterone supplementation, groups A and B showed a highly significant reduction in RI, PI and an increase in EDV. A relative increase in the value of PSV was observed in group A as compared to group B. There was remarkable difference in S/D in both groups. Although not statistically significant, group C showed reduction in RI, PI, PSV, EDV and S/D ratio. Pregnancy salvage rates were higher in group A (92.0%) as compared to group B (82.3%). CONCLUSION: Progesterone supplementation appears to lower vascular resistance in women with IRSM. Oral dydrogesterone appears to be equally effective in improving endometrial blood flow as compared with micronized progesterone.

Comparison of the effect of dydrogesterone and natural micronized progesterone for luteal-phase support in assisted reproductive technology cycles: A single-blind randomized clinical trial study.

Background and Aims: One of the causes of preterm labor and recurrent abortion is progesterone deficiency in the luteal phase. The aim of the study was a comparison of the effect of oral dydrogesterone and vaginal progesterone for luteal-phase support (LPS) in assisted reproductive technology cycles (ART). Methods: This randomized clinical control trial study was conducted on 207 infertile women. Samples were randomly divided into two groups. The first group received a natural micronized vaginal progesterone (MVP) of 400 mg once daily and the second group received dydrogesterone (Duphestone) 20 mg twice daily. Then chemical pregnancy, abortion, and live births were compared in two groups. Results: The results of the study showed that the vaginal form of the drug could increase the chance of pregnancy (positive ß-human chorionic gonadotropin) versus the oral form. According to the results of multiple logistic regression analysis after adjusting for other variables, the live birth rate in the vaginal group was more than five times that of the oral group (odds ratio = 5.07; 95% confidence interval = 1.24-20.65; p = 0.023). Conclusion: The vaginal form of the progesterone could increase the chance of pregnancy and the outcome of fertility (live birth). Thus, vaginal progesterone is effective for LPS in women undergoing fresh embryo transfer.

Can we improve the outcome of pregnancies with low serum PAPP-A in the first trimester?

OBJECTIVE: This study aimed to assess the impact of micronized progesterone (VMP4) supplementation on pregnancies with low serum pregnancy-associated plasma protein-A (PAPP-A) multiples of the median (MoM) values during first-trimester screening. METHODS: Out of 8933 patients evaluated, 116 pregnant women with low PAPP-A concentrations in their blood and no fetal chromosomal anomalies (CAs) were included. Three groups were formed: group 1 received VMP4 from 11 to 16 weeks (29 women, 25%), group 2 received VMP4 from 11 to 36 weeks (25 women, 21.5%), and group 3 (62 women, 53.5%) served as controls without receiving progesterone. RESULTS: Results indicated that group 3 had higher rates of complications, including miscarriages (16.37%), preterm delivery (17.8%), and fetal developmental abnormalities (19.4%). Birthweight variations were elevated in pregnancies without progesterone, contrasting with lower variations in VMP4 groups. Group 2, receiving VMP4 until 36 weeks, reported the lowest incidence of abortion and preterm birth (PB), along with the highest mean birth weight. CONCLUSIONS: The conclusion suggests that 200 mg per day of VMP4 up to 36 weeks of supplementation led to fewer placental-related complications in women with very low PAPP-A at first-trimester screening (0.399 MoM). By reporting lower rates of miscarriages, PBs, and fetal developmental abnormalities in the micronized progesterone-treated groups, the study suggests a potential reduction in complications.

A randomised control trial on oral dydrogesterone versus micronized vaginal progesterone pessary for luteal phase support in in vitro fertilization cycles.

This study aimed to evaluate the pregnancy rates, adverse reactions, and medication costs of two luteal phase support regimens: oral dydrogesterone and micronized vaginal progesterone (MVP) pessary in in vitro fertilization cycles. A randomized open-label trial with participants randomly assigned to either 400 mg MVP twice daily or 10 mg dydrogesterone three times daily. The primary endpoints were pregnancy rates, and the secondary endpoints included tolerance, miscarriage rates, and medication cost. Per-protocol principle analysis was performed. The baseline characteristics of the 162 participants were similar. Dydrogesterone had statistically similar (p>0.05) positive pregnancy test rates fifteen days post embryo transfer (35.8% vs. 32.7%), clinical pregnancy rates at the gestational age of 6 weeks (32.1% vs. 28.8%), ongoing pregnancy rates (26.4% vs. 23.1%) and miscarriage rates at 14 weeks of gestation (9.2% vs. 9.4%) and safety profile to MVP. Dydrogesterone was better tolerated as vaginal itching was significantly more prevalent in the MVP arm (p=0.008). Dydrogesterone is significantly less expensive than MVP pessary. Oral dydrogesterone and MVP pessary had similar pregnancy rates and adverse effects. Dydrogesterone appears more user-friendly and less expensive in cases of luteal-phase support in in vitro fertilization cycles.

Serum progesterone concentration on pregnancy test day might predict ongoing pregnancy after controlled ovarian stimulation and fresh embryo transfer.

Progesterone (P4) is essential for pregnancy. A controlled ovarian stimulation (COS) leads to a iatrogenic luteal defect that indicates a luteal phase support (LPS) at least until pregnancy test day. Some clinicians continue the LPS until week 8 or later, when P4 is mainly secreted by syncytiotrophoblast cells.Measuring serum P4 on pregnancy test day after a fresh embryo transfer could help to identify women who might benefit from prolonged LPS. In women with LPS based on P4 administered by the rectal route, P4 concentration on pregnancy test day was significantly higher in patients with ongoing pregnancy than in patients with abnormal pregnancy.This monocentric retrospective study used data on 99 consecutive cycles of COS, triggered with human chorionic gonadotropin, followed by fresh embryo transfer resulting in a positive pregnancy test (>100 IU/L) (from November 2020 to November 2022). Patients undergoing preimplantation genetic screening or with ectopic pregnancy were excluded. All patients received standard luteal phase support (i.e. micronized vaginal progesterone 600 mg per day for 15 days). The primary endpoint was P4 concentration at day 15 after oocyte retrieval (pregnancy test day) in women with ongoing pregnancy for >12 weeks and in patients with miscarriage before week 12 of pregnancy.The median P4 concentration [range] at pregnancy test day was higher in women with ongoing pregnancy than in women with miscarriage (55.9 ng/mL [11.6; 290.6] versus 18.1 ng/mL [8.3; 140.9], p = 0.002). A P4 concentration ≥16.5 ng/mL at pregnancy test day was associated with higher ongoing pregnancy rate (OR = 12.5, 95% CI 3.61 - 43.33, p <0.001). A P4 concentration ≥16.5 ng/mL at pregnancy test day was significantly associated with higher live birth rate (OR = 11.88, 95% CI 3.30-42.71, p <0.001).After COS and fresh embryo transfer, the risk of miscarriage is higher in women who discontinue luteal support after 15 days, as recommended, but with P4 concentration <16.5 ng/mL. The benefit of individualized prolonged luteal phase support should be evaluated.