A 10-year follow-up on the practice of luteal phase support using worldwide web-based surveys

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.

Luteal phase support in assisted reproductive technology centers: Italian survey

BACKGROUND

In assisted reproductive cycles (ART), the fine balance of controlling corpus luteum function is severely disrupted. To challenge this iatrogenic deficiency, clinicians aim to provide exogenous support. Several reviews have investigated progesterone route of administration, dosage and timing.

METHODS

A survey about luteal phase support (LPS) after ovarian stimulation was conducted among doctors in charge in Italian II-III level ART centers.

RESULTS

With regards to the general approach to LPS, 87.9% doctors declare to diversify the approach; the reasons for diversifying (69.7%) were based on the type of cycle. For all the most important administration routes (vaginal, intramuscular, subcutaneous) it appears that in frozen cycles there is a shift towards higher dosages. The 90.9% of the centers use vaginal progesterone, and when a combined approach is required, in 72.7% of cases vaginal administration is combined with injective route of administration. When Italian doctors were asked about the beginning and duration of LPS, 96% of the centers start the day of the pickup or the day after, while 80% of the centers continue LPS until week 8-12. The rate of participation of the centers confirms the low perceived importance of LPS among Italian ART centers, while may be considered quite surprising the relatively higher percentage of centers that measures P level. Tailorization to women's needs is the new objective of LPS: self-administration, good tolerability are the main aspects for Italian centers.

CONCLUSIONS

In conclusion, results of Italian survey are consistent to results of main international surveys about LPS.

No additional risk of congenital anomalies after first-trimester dydrogesterone use: a systematic review and meta-analysis

STUDY QUESTION

Is exposure to dydrogesterone a risk factor for congenital anomalies when given in the first trimester for recurrent/threatened pregnancy loss or as luteal support in assisted reproductive technology (ART)?

SUMMARY ANSWER

Dydrogesterone, when given in the first trimester for recurrent/threatened pregnancy loss or as luteal support in ART, is not a relevant additional risk factor for congenital anomalies.

WHAT IS KNOWN ALREADY

Despite large clinical trials and meta-analyses that show no association between dydrogesterone and congenital anomalies, some recently retracted publications have postulated an association with teratogenicity. Dydrogesterone is also often rated as less safe than bioidentical progestins.

STUDY DESIGN SIZE DURATION

A systematic review was conducted according to a pre-specified protocol with searches on Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Clinicaltrials.gov. The search was limited to human studies, with no restrictions on language, geographical region, or date. The search algorithm used a PICO (Population, Intervention, Comparison, Outcome)-style approach combining both simple search terms and medical subject heading terms. As congenital anomalies are mostly reported as secondary outcomes, the search term 'safety' was added.

PARTICIPANTS/MATERIALS SETTING METHODS

Interventional study and observational study (OS) designs were eligible for inclusion. Inclusion criteria were: women >17 years old treated for threatened miscarriage, recurrent pregnancy loss, and/or ART; the use of dydrogesterone in the first trimester compared with placebo, no treatment or other interventions; and reporting of congenital anomalies in newborns or infants ≤12 months old (primary outcome). Two authors (A.K., M.R.N.) independently extracted the following data: general study information, study population details, intervention and comparator(s), and frequencies of congenital anomalies (classification, time of determination, and type). Risk of bias focused on the reporting of congenital malformations and was assessed using the Cochrane Risk of Bias Tool Version 2 or the ROBINS-I tool. The GRADEproGDT platform was used to generate the GRADE summary of findings table.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 897 records retrieved during the literature search, 47 were assessed for eligibility. Nine studies were included in the final analysis: six randomized controlled trials (RCTs) and three OSs. Among the RCTs, three had a low risk and three a high risk of bias. Two of the OSs were considered to have a serious risk of bias and one with critical risk of bias and was excluded for the evidence syntheses. The eight remaining studies included a total of 5070 participants and 2680 live births from 16 countries. In the meta-analysis of RCTs only, the overall risk ratio (RR) was 0.92 [95% CI 0.55; 1.55] with low certainty. When the two OSs were included, the overall RR was 1.11 [95% CI 0.73; 1.68] with low certainty.

LIMITATIONS REASONS FOR CAUTION

The studies included in the analysis do not report congenital anomalies as the primary outcome; reporting of congenital anomalies was often not standardized.

WIDER IMPLICATIONS OF THE FINDINGS

This systematic literature review and meta-analysis provide clear reassurance to both clinicians and patients that dydrogesterone is not associated with congenital anomalies above the rate that might be expected due to environmental and genetic factors. The results of this work represent the highest current level of evidence for the question of congenital anomalies, which removes the existing uncertainty caused by poor quality and retracted studies.

STUDY FUNDING/COMPETING INTERESTS

Editorial support was provided by Highfield Communication Consultancy, Oxford, UK, sponsored by Abbott Products Operations AG, Allschwil, Switzerland. A.K., J.A.G.-V., L.P.S., J.N.v.d.A., and J.F.S. received honoraria from Abbott for preparation and participation in an advisory board. J.A.G.-V. received grants and lecture fees from Merck, Organon, Ferring, Gedeon Richter, and Theramex. M.R.N. has no conflicts of interest. J.N.v.d.A. and J.A.G.-V. have no other conflicts of interest. A.K. received payment from Abbott for a talk at the IVF Worldwide congress on 22 September 2023. J.F.S. has received grants from the National Institutes of Health, royalties/licences from Elsevier and Prescient Medicine (SOLVD Health), consulting fees from Burroughs Wellcome Fund (BWF) and Bayer, honoraria from Magee Women's Research Institute, Wisconsin National Primate Research Centre, University of Kansas and Oakridge National Research Laboratory, Agile, Daiichi Sankyo/American Regent, and Bayer, and travel support to attend meetings for the International Academy of Human Reproduction (IAHR). J.F.S. has patents related to diagnosis and treatment of PCOS and prediction of preterm birth. J.F.S. participates on advisory boards for SOLVD Health, Wisconsin National Primate Research Centre, and FHI360, was the past President board member of the Society for Reproductive Investigation, has a leadership role for the following organizations: Scientific Advisory Board, SOLVD Health, EAB Chair for contraceptive technology initiative, FHI360, EAB member, Wisconsin National Primate Research Centre, Advisory Board for MWRI Summit, Chair of BWF NextGen Pregnancy Research Panel, Medical Executive Committee at the Howard, and Georgeanna Jones Foundation, and is Vice President, IAHR. L.P.S. has received consulting fees from Shield Pharmaceuticals, Scynexis, Organon, Natera, Celula China, AiVF, Agile, Daiichi Sankyo, American Regent, and Medicem, honoraria from Agile, Daiichi Sankyo/American Regent, and Bayer, and travel support from BD Diagnostics. L.P.S. participates on the data safety monitoring board for Astellas and is a Chair of DSMB for fezolinetant. Abbott played no role in the funding of the study or in study design, data collection, data analysis, data interpretation, or writing of the report.

TRIAL REGISTRATION NUMBER

PROSPERO 2022 CRD42022356977.

Progesterone Hypersensitivity in Assisted Reproductive Technologies: Implications for Safety and Efficacy

The global rise in the age of childbirth, influenced by changing sociodemographic patterns, has had a notable impact on fertility rates. Simultaneously, assisted reproductive techniques (ARTs) have become increasingly prevalent due to advancements in reproductive medicine. The paper explores the intersection between the surge in ARTs and the rising number of iatrogenic autoimmune progesterone dermatitis (APD). Autoimmune progesterone dermatitis, commonly known as progesterone hypersensitivity, manifests itself as a mucocutaneous hypersensitivity syndrome. It is characterized by a wide range of dermatological symptoms, with urticaria and maculopapular rashes being the most prominent signs. Concurrently, systemic symptoms, such as fever, angioedema, and, in severe instances, anaphylaxis, may ensue. This dermatologic condition poses a significant challenge to women of childbearing age. This intricate syndrome frequently manifests itself in conjunction with menstruation or pregnancy as a reaction to physiological fluctuations in endogenous progesterone. However, given that exposure to exogenous progesterone is an integral component of various modern therapies, secondary APD has also been described. Our findings unveil a heightened likelihood of developing secondary progesterone hypersensitivity in ART patients that is attributed to the administration of exogenous progesterone through intramuscular, intravaginal, and oral routes. The study also explores available therapeutic interventions for facilitating viable pregnancies in individuals grappling with autoimmune progesterone dermatitis within the context of ARTs. This comprehensive analysis contributes valuable insights into the intricate relationship between reproductive technologies, dermatological challenges, and successful pregnancy outcomes.

Oral micronized progesterone versus vaginal progesterone for luteal phase support in fresh embryo transfer cycles: a multicenter, randomized, non-inferiority trial

STUDY QUESTION

Does oral micronized progesterone result in a non-inferior ongoing pregnancy rate compared to vaginal progesterone gel as luteal phase support (LPS) in fresh embryo transfer cycles?

SUMMARY ANSWER

The ongoing pregnancy rate in the group administered oral micronized progesterone 400 mg per day was non-inferior to that in the group administered vaginal progesterone gel 90 mg per day.

WHAT IS KNOWN ALREADY

LPS is an integrated component of fresh IVF, for which an optimal treatment regimen is still lacking. The high cost and administration route of the commonly used vaginal progesterone make it less acceptable than oral micronized progesterone; however, the efficacy of oral micronized progesterone is unclear owing to concerns regarding its low bioavailability after the hepatic first pass.

STUDY DESIGN, SIZE, DURATION

This non-inferiority randomized trial was conducted in eight academic fertility centers in China from November 2018 to November 2019. The follow-up was completed in April 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 1310 infertile women who underwent their first or second IVF cycles were enrolled. On the day of hCG administration, the patients were randomly assigned to one of three groups for LPS: oral micronized progesterone 400 mg/day (n = 430), oral micronized progesterone 600 mg/day (n = 440) or vaginal progesterone 90 mg/day (n = 440). LPS was started on the day of oocyte retrieval and continued till 11-12 weeks of gestation. The primary outcome was the rate of ongoing pregnancy.

MAIN RESULTS AND THE ROLE OF CHANCE

In the intention-to-treat analysis, the rate of ongoing pregnancy in the oral micronized progesterone 400 mg/day group was non-inferior to that of the vaginal progesterone gel group [35.3% versus 38.0%, absolute difference (AD): -2.6%; 95% CI: -9.0% to 3.8%, P-value for non-inferiority test: 0.010]. There was insufficient evidence to support the non-inferiority in the rate of ongoing pregnancy between the oral micronized progesterone 600 mg/day group and the vaginal progesterone gel group (31.6% versus 38.0%, AD: -6.4%; 95% CI: -12.6% to -0.1%, P-value for non-inferiority test: 0.130). In addition, we did not observe a statistically significant difference in the rate of live births between the groups.

LIMITATIONS, REASONS FOR CAUTION

The primary outcome of our trial was the ongoing pregnancy rate; however, the live birth rate may be of greater clinical interest. Although the results did not show a difference in the rate of live births, they should be confirmed by further trials with larger sample sizes. In addition, in this study, final oocyte maturation was triggered by hCG, and the findings may not be extrapolatable to cycles with gonadotropin-releasing hormone agonist triggers.

WIDER IMPLICATIONS OF THE FINDINGS

Oral micronized progesterone 400 mg/day may be an alternative to vaginal progesterone gel in patients reluctant to accept the vaginal route of administration. However, whether a higher dose of oral micronized progesterone is associated with a poorer pregnancy rate or a higher rate of preterm delivery warrants further investigation.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by a grant from the National Natural Science Foundation of China (82071718). None of the authors have any conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

This trial was registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn/) with the number ChiCTR1800015958.

TRIAL REGISTRATION DATE

May 2018.

DATE OF FIRST PATIENT’S ENROLMENT

November 2018.

Interventions to prevent or reduce the incidence and severity of ovarian hyperstimulation syndrome: a systematic umbrella review of the best clinical evidence

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threating iatrogenic complication of the early luteal phase and/or early pregnancy after in vitro fertilization (IVF) treatment. The aim of the current study was to identify the most effective methods for preventing of and reducing the incidence and severity of OHSS in IVF patients. A systematic review of systematic reviews of randomized controlled trials (RCTs) with meta-analysis was used to assess each potential intervention (PROSPERO website, CRD 268626) and only studies with the highest quality were included in the qualitative analysis. Primary outcomes included prevention and reduction of OHSS incidence and severity. Secondary outcomes were maternal death, incidence of hospital admission, days of hospitalization, and reproductive outcomes, such as incidence of live-births, clinical pregnancies, pregnancy rate, ongoing pregnancy, miscarriages, and oocytes retrieved. A total of specific interventions related to OHSS were analyzed in 28 systematic reviews of RCTs with meta-analyses. The quality assessment of the included studies was high, moderate, and low for 23, 2, and 3 studies, respectively. The certainty of evidence (CoE) for interventions was reported for 37 specific situations/populations and resulted high, moderate, and low-to-very low for one, 5, and 26 cases, respectively, while it was not reported in 5 cases. Considering the effective interventions without deleterious reproductive effects, GnRH-ant co-treatment (36 RCTs; OR 0.61, 95% C 0.51 to 0.72, n = 7,944; I² = 31%) and GnRH agonist triggering (8 RCTs; OR 0.15, 95% CI 0.05 to 0.47, n = 989; I² = 42%) emerged as the most effective interventions for preventing OHSS with a moderate CoE, even though elective embryo cryopreservation exhibited a low CoE. Furthermore, the use of mild ovarian stimulation (9 RCTs; RR 0.26, CI 0.14 to 0.49, n = 1,925; I² = 0%), and dopaminergic agonists (10 RCTs; OR 0.32, 95% CI 0.23 to 0.44, n = 1,202; I² = 13%) coadministration proved effective and safe with a moderate CoE. In conclusion, the current study demonstrates that only a few interventions currently can be considered effective to reduce the incidence of OHSS and its severity with high/moderate CoE despite the numerous published studies on the topic. Further well-designed RCTs are needed, particularly for GnRH-a down-regulated IVF cycles.

The effect of frozen embryo transfer regimen on the association between serum progesterone and live birth: a multicentre prospective cohort study (ProFET)

STUDY QUESTION

What is the association between serum progesterone levels on the day of frozen embryo transfer (FET) and the probability of live birth in women undergoing different FET regimens?

SUMMARY ANSWER

Overall, serum progesterone levels <7.8 ng/ml were associated with reduced odds of live birth, although the association between serum progesterone levels and the probability of live birth appeared to vary according to the route of progesterone administration.

WHAT IS KNOWN ALREADY

Progesterone is essential for pregnancy success. A recent systematic review showed that in FET cycles using vaginal progesterone for endometrial preparation, lower serum progesterone levels (<10 ng/ml) were associated with a reduction in live birth rates and higher chance of miscarriage. However, there was uncertainty about the association between serum progesterone levels and treatment outcomes in natural cycle FET (NC-FET) and HRT-FET using non-vaginal routes of progesterone administration.

STUDY DESIGN SIZE DURATION

This was a multicentre (n = 8) prospective cohort study conducted in the UK between January 2020 and February 2021.

PARTICIPANTS/MATERIALS SETTING METHODS

We included women having NC-FET or HRT-FET treatment with progesterone administration by any available route. Women underwent venepuncture on the day of embryo transfer. Participants and clinical personnel were blinded to the serum progesterone levels. We conducted unadjusted and multivariable logistic regression analyses to investigate the association between serum progesterone levels on the day of FET and treatment outcomes according to the type of cycle and route of exogenous progesterone administration. Our primary outcome was the live birth rate per participant.

MAIN RESULTS AND THE ROLE OF CHANCE

We studied a total of 402 women. The mean (SD) serum progesterone level was 14.9 (7.5) ng/ml. Overall, the mean adjusted probability of live birth increased non-linearly from 37.6% (95% CI 26.3-48.9%) to 45.5% (95% CI 32.1-58.9%) as serum progesterone rose between the 10th (7.8 ng/ml) and 90th (24.0 ng/ml) centiles. In comparison to participants whose serum progesterone level was ≥7.8 ng/ml, those with lower progesterone (<7.8 ng/ml, 10th centile) experienced fewer live births (28.2% versus 40.0%, adjusted odds ratio [aOR] 0.41, 95% CI 0.18-0.91, P = 0.028), lower odds of clinical pregnancy (30.8% versus 45.1%, aOR 0.36, 95% CI 0.16-0.79, P = 0.011) and a trend towards increased odds of miscarriage (42.1% versus 28.7%, aOR 2.58, 95% CI 0.88-7.62, P = 0.086). In women receiving vaginal progesterone, the mean adjusted probability of live birth increased as serum progesterone levels rose, whereas women having exclusively subcutaneous progesterone experienced a reduction in the mean probability of live birth as progesterone levels rose beyond 16.3 ng/ml. The combination of vaginal and subcutaneous routes appeared to exert little impact upon the mean probability of live birth in relation to serum progesterone levels.

LIMITATIONS REASONS FOR CAUTION

The final sample size was smaller than originally planned, although our study was adequately powered to confidently identify a difference in live birth between optimal and inadequate progesterone levels. Furthermore, our cohort did not include women receiving oral or rectal progestogens.

WIDER IMPLICATIONS OF THE FINDINGS

Our results corroborate existing evidence suggesting that lower serum progesterone levels hinder FET success. However, the relationship between serum progesterone and the probability of live birth appears to be non-linear in women receiving exclusively subcutaneous progesterone, suggesting that in this subgroup of women, high serum progesterone may also be detrimental to treatment success.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by CARE Fertility and a doctoral research fellowship (awarded to P.M.) by the Tommy's Charity and the University of Birmingham. M.J.P. is supported by the NIHR Birmingham Biomedical Research Centre. S.F. is a minor shareholder of CARE Fertility but has no financial or other interest with progesterone testing or manufacturing companies. P.L. reports personal fees from Pharmasure, outside the submitted work. G.P. reports personal fees from Besins Healthcare, outside the submitted work. M.W. reports personal fees from Ferring Pharmaceuticals, outside the submitted work. The remaining authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT04170517.

Impact of different endometrial preparation protocols before frozen embryo transfer on pregnancy outcomes: a review

The use of frozen embryo transfer cycles has exponentially increased in the last few years. Optimization of endometrial preparation protocols before frozen embryo transfer is mandatory to further improve pregnancy outcomes. This review will focus on the existing literature with regard to the different available endometrial preparation protocols and their impact on pregnancy outcomes. More specifically, we will focus on programmed, natural, and stimulated frozen embryo transfer cycles. The studies performed on this topic are generally of low quality, and only a few well-performed randomized controlled trials have been published. To date, no strong evidence is available to support the use of 1 preparation method over another in terms of pregnancy outcomes. However, robust data have shown a clearly protective effect of natural frozen embryo transfer cycles against long-term obstetric complications, mainly hypertensive disorders of pregnancy and large for gestational age infants. The introduction of individualized luteal phase support in different endometrial preparation protocols is actually gaining a lot of attention and requires further investigation.

Systematic use of long-acting intramuscular progesterone in addition to oral dydrogesterone as luteal phase support for single fresh blastocyst transfer: A pilot study

OBJECTIVE

The need of luteal support after FET is no longer to be proven. Different routes of progesterone administration are available with interindividual differences in metabolization and serum progesterone levels, the latter being highly correlated with pregnancy and delivery rates. The administration of 2 different routes of progestogen significantly improves success rates in FET. The aim of the current study was to investigate the added value to combine intramuscular administration of progesterone to dydrogesterone in fresh embryo transfer.

METHODS

This is a retrospective study from prospectively collected data. Patient, aged between 18 and 43 years old, had received a fresh blastocyst transfer between January 2021 and June 2021. In the first group, all patients received only oral dydrogesterone 10mg, three times a day, beginning the evening of oocyte retrieval. In the second group, patients received, in addition to dydrogesterone, a weekly intramuscular injection of progesterone started the day of embryo transfer. Primary endpoint was ongoing pregnancy rate.

RESULTS

171 fresh single blastocyst transfers have been performed during this period. 82 patients were included in "dydrogesterone only" and 89 patients in "dydrogesterone + IM". Our two groups were comparable except for body mass index. After adjustment on BMI, our two groups were comparable regarding implantation rate, early pregnancy rate (46.1 versus 54.9, OR 1.44 [0.78; 2.67], p=0.25) miscarriage rate, ongoing pregnancy rate (30.3 versus 43.9, OR 1.85 [0.97; 3.53] p= 0.06).

CONCLUSION

Using systematically long acting intramuscular progesterone injection in addition to oral dydrogesterone as luteal phase support seems to have no significant impact on IVF outcomes when a single fresh blastocyst transfer is performed.

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.

Early-Pregnancy Dydrogesterone Supplementation Mimicking Luteal-Phase Support in ART Patients Did Not Provoke Major Reproductive Disorders in Pregnant Mice and Their Progeny

Progestogens are frequently administered during early pregnancy to patients undergoing assisted reproductive techniques (ART) to overcome progesterone deficits following ART procedures. Orally administered dydrogesterone (DG) shows equal efficacy to other progestogens with a higher level of patient compliance. However, potential harmful effects of DG on critical pregnancy processes and on the health of the progeny are not yet completely ruled out. We treated pregnant mice with DG in the mode, duration, and doses comparable to ART patients. Subsequently, we studied DG effects on embryo implantation, placental and fetal growth, fetal-maternal circulation, fetal survival, and the uterine immune status. After birth of in utero DG-exposed progeny, we assessed their sex ratios, weight gain, and reproductive performance. Early-pregnancy DG administration did not interfere with placental and fetal development, fetal-maternal circulation, or fetal survival, and provoked only minor changes in the uterine immune compartment. DG-exposed offspring grew normally, were fertile, and showed no reproductive abnormalities with the exception of an altered spermiogram in male progeny. Notably, DG shifted the sex ratio in favor of female progeny. Even though our data may be reassuring for the use of DG in ART patients, the detrimental effects on spermatogenesis in mice warrants further investigations and may be a reason for caution for routine DG supplementation in early pregnancy.