Luteal phase defect: the sensitivity and specificity of diagnostic methods in common clinical use

Exogenous progesterone rescue in patients with low mid-luteal serum progesterone levels undergoing true natural vitrified-warmed blastocyst transfer

PURPOSE

To explore whether a 25 mg subcutaneous progesterone daily rescue daily improves the reproductive outcomes in patients with low serum progesterone (P4) levels (7-10 ng/mL), measured one day before true natural cycle (t-NC) frozen embryo transfer (FET).

METHODS

A cohort study of 192 women undergoing t-NC warmed blastocyst transfer. Patients were stratified into three different groups based on serum P4 levels on the FET-1 day: patients who had serum P4 levels of 7-10 ng/mL and underwent rescue progesterone administration (rescue group), patients with serum P4 levels of 7-10 ng/mL without progesterone administration (non-rescue group), and patients with serum P4 > 10 ng/mL on FET-1 day (control group). The primary outcome was possible differences in live birth rate (LBR) between groups.

RESULTS

The LBRs for the serum P4 7-10 ng/mL without rescue, 7-10 ng/mL with rescue, and > 10 ng/mL (control) groups were 41%, 46%, and 52%, respectively (p = 0.61). The estimated adjusted probability of live birth for serum P4 7-10 ng/mL without rescue, 7-10 ng/mL with rescue, and > 10 ng/mL (control) groups were also comparable: 43.5% (95% CI, 20.0-70.4%), 49.8% (95% CI, 28.1-71.6%), and 57.4% (95% CI, 44.0-69.8%), respectively.

CONCLUSION

Serum P4 levels higher than 7 ng/mL seem to secure LBRs in patients undergoing t-NC FET. A rescue policy consisting of a daily subcutaneous 25 mg progesterone dose in patients with serum P4 levels 7-10 ng/mL does not further enhance LBRs when compared to those patients with similar serum P4 levels without rescue.

High serum progesterone levels on the day of embryo transfer in patients undergoing artificial frozen-thawed blastocyst transfer: Is there a ceiling effect?

Objective

To evaluate the potential ceiling effect of high serum progesterone levels on the day of embryo transfer for pregnancy outcomes in patients undergoing artificial frozen-thawed blastocyst transfer (FET) cycles.

Materials and Methods

This retrospective cohort study included 595 patients who underwent artificial FET cycles. We evaluated progesterone levels and found that 40.6 ng/mL corresponded to the 90th percentile and 23.9 ng/mL corresponded to the 50th percentile. Based on these findings, we categorized progesterone levels as <20 ng/mL (n=220, 37.0%), 20-40 ng/mL (n=312, 52.4%), and ≥40 ng/mL (n=63, 10.6%). The primary outcome measures were the clinical pregnancy rate (CPR) and live birth rate (LBR).

Results

Blastocyst morphology grades, including expansion, trophectoderm, and inner cell mass grades, were significantly associated with clinical pregnancy (p<0.001 for all). Progesterone levels between 20 and 40 ng/mL were associated with higher CPR (p=0.043). In the multivariate analysis, only blastocyst expansion and inner cell mass grades were independently and significantly associated with CPR [p=0.011, odds ratio (OR)=1.6, (confidence interval) CI 95%=1.13-2.39, and p=0.007, OR=1.65, CI 95%=1.14-2.39, respectively]. The progesterone level and trophectoderm grade were not statistically significant. Regarding LBR, only blastocyst expansion grades 4 and trophectoderm grades A or B were significantly associated.

Conclusion

Based on these data, we speculate that if serum progesterone levels exceed 40 ng/mL on the day of embryo transfer in patients undergoing artificial FET cycles, there is no need to reduce the progesterone dose.

Progesterone in frozen embryo transfer cycles: assays, circulating concentrations, metabolites, and molecular action

Programmed or medicated frozen embryo transfer cycles rely on exogenous progesterone (P) administration to prepare the endometrium for implantation and maintain pregnancy. Presently, the optimal route and dose of P replacement for frozen embryo transfer are not known. In addition, there is a paucity of data and insufficient understanding regarding the metabolism and actions of P in implantation and pregnancy maintenance. In the present review, we discuss how different P assay methodologies affect the determination of P thresholds for implantation and pregnancy maintenance. In addition, we discuss the importance of free P and its regulation in the endometrium and show the complexity of molecular signaling that is required for P-dependent endometrial receptivity. We concluded that future studies should focus on defining accurate circulating and endometrial P concentrations, both for total and free P, and how these concentrations correlate with endometrial receptivity and clinical outcomes.

Hotspots and frontiers in luteal phase defect research: An in-depth global trend bibliometric and visualization analysis over a 52-year period

Luteal phase defect (LPD) is a common female reproductive endocrine defect，which is associated not only with certain diseases but also with the menstrual cycle and fertility in women. With the development of assisted reproductive technology (ART) in recent years, the incidence of luteal phase defect is high among patients using assisted reproductive technology. The aim of this study was to evaluate worldwide research on luteal phase defects using bibliometric analysis. A total of 631 documents related to the study of luteal phase defect were identified over the last 52 years. The current status and trend of globalization can be comprehended by analyzing the annual number of publications, institutions, authors, countries and regions of corresponding authors, journals, influential luteal phase defect publications (which were highly cited), highly cited references in luteal phase defect publications (cocitation analysis) and keywords. The study results provide a comprehensive overview of the development of scientific literature and are of great significance for the future development of the field，especially infertility and early pregnancy loss.

Low Dose hCG Support in Modified Natural Frozen Embryo Transfer Cycles

What is the effect of a single low-dose recombinant hCG injection after embryo transfer (ET) in letrozole-induced modified natural frozen embryo transfer cycles (mNC-FET)?. An observational study was conducted in the university-affiliated referral clinic between 2022 and 2024. Women aged 18-42 with at least one vitrified blastocyst obtained from the previous cycle(s) were included. Ovulation induction for endometrial preparation was initiated with oral letrozol (5 mg/day) for five days. Ovulation was triggered using 6500 IU rec hCG sc when the leading follicle > 17 mm, endometrial thickness > 7.5 mm, and serum progesterone (P) < 1.5 ng/ml. All women received 30 mg dydrogesterone/day po for additional five-day luteal support. On the 6th day, ET was performed. Based on a quasi-randomized design, a group of women additionally received a half single bolus of (3250 IU) rec hCG (sc) on the morning of 3rd day of ET (hCG group). Women who did not receive additional hCG were assigned as controls. One hundred fifty-four women were detected to be eligible for the study among 2150 initiated FET cycles during the period. Demographic data of the groups, including mean women's age, BMI, serum AMH, and infertility etiologies, were comparable in terms of variables. Mean serum progesterone values and the number of transferred embryos were also similar. A significantly higher ongoing pregnancy/started cycle was documented in the hCG group than in controls (46.7% vs 33.6% respectively, p = 0.03*). A single low-dose hCG injection after ET may improve the OPRs of women in letrozole mNC-FET cycles.

The natural menstrual cycle revisited - can natural cycle be trusted

BACKGROUND

The serum progesterone (P4) level during the luteal phase (LP) plays a crucial role in the initiation and maintenance of pregnancy. However, it is unclear whether the natural cycle consistently provides the best endocrine profile and whether mid-luteal serum P4 levels are always sufficient to support implantation and early pregnancy. The question has become more relevant in relation to fertility treatment, as more frozen embryo transfer cycles are performed in the natural cycle. Moreover, can serum hormone levels and covariates measured during the follicular phase (FP), such as Follicle Stimulation Hormone (FSH), Luteinizing Hormone (LH), Estradiol (E2), Anti-Mullerian Hormone (AMH) and Antral Follicle Count (AFC), be used to predict P4 levels during the luteal phase (LP)?

RESULTS

This observational prospective cohort study analysed 26 healthy women with a cycle length between 21-35 days and a body mass index (BMI) < 30 kg/m2. Blood sampling started on the fifth day of the menstrual cycle and continued every fifth day until the next cycle. The procedure was repeated for a total of three cycles. The study found that only ten women had a P4 level greater than 30 nmol/L on cycle day 20 or 25 in all three cycles. In total, only 45 cycles out of 77 cycles had serum P4 levels ≥ 30 nmol/L. The E2 level ≥ 345 pmol/L on cycle day 10 proved to be predictive of a P4 level of ≥ 30 nmol/L on either day 20 or day 25 with a sensitivity of 57% and a specificity of 89%. No other covariates, including the FSH level cycle day 5, LH levels during the follicular phase, age, weight, AFC and AMH cycle day 5 correlated with LP P4 levels.

CONCLUSIONS

A significant correlation between FP E2 levels cycle day 5 (> 131pmol/L) and cycle day 10 (> 345pmol/L) and a LP P4 level ≥ 30 nmol/l was found; thus, the FP E2 level is a predictor of corpus luteum competence. Our findings highlight the existence of suboptimal P4 levels during the LP and a significant inter-individual and intra-cycle variation in P4 levels during the LP in regular menstruating women.

Effects of a Preseason Neuromuscular Training Program vs. an Endurance-Dominated Program on Physical Fitness and Injury Prevention in Female Soccer Players

BACKGROUND

The pre-season preparatory period is considered key for optimizing the physical fitness levels needed to withstand congested match periods and preventing injuries during the regular soccer season. This study contrasted the effects s of neuromuscular training (NMT) versus an endurance-dominated training (ET) program conducted during the preseason on measures of physical fitness and injury occurrence in female soccer players.

METHODS

Twenty-four female soccer players aged 17.0 ± 1.3 years from a professional soccer club participated in this study. Players were randomly assigned to NMT (n = 12) or ET (n = 12) groups according to their playing position. The preseason intervention program lasted six weeks, with three weekly sessions with a duration of 45-60 min per session. Exercises in the NMT group included muscle strengthening exercises, plyometrics, agility and dynamic stability exercises, while the ET group practiced a traditional pre-season training program consisting of running and sprinting exercises, fartlek, and high-intensity interval training. The training volumes were similar in the two study groups. Anthropometric measurements, physical fitness tests (i.e., linear and change-of-direction speed, muscle strength and power tests) and the overall injury rate per 1000 h of exposure (training, match) were recorded throughout the season.

RESULTS

No between group differences were found at pre (T1). Significant group-by-time interactions were observed for the 5, 10, and 30-m linear sprint speed tests (p < 0.001, 2.16 < d < 2.58), the T-test (p = 0.024, d = 1.03), the squat (p < 0.001, d = 4.04), and the countermovement jump test (p < 0.001, d = 2.21), the Loughborough soccer passing test (LSPT) (p = 0.019, d = 1.08), and the 1-RM back squat test (p < 0.001, d = 2.53). Post-hoc tests indicated that NMT provided larger improvements for SJ, CMJ, 1-RM back squat, the 5-m sprint, 10-m sprint, 30-m sprint, T-test and LSPT compared to ET (1.07 > d > 2.77). The injury rate across the season was significantly lower in the NMT (5.1/1000 h exposure) compared to ET (11.8/1000 h exposure) (p = 0.014).

CONCLUSIONS

The findings support that six-weeks of preseason NMT versus ET induced larger performance improvements, and significantly reduced injury occurrence in elite female soccer players.

Luteal phase support of intramuscular progesterone associated with lower hypertensive disorders of pregnancy as compared to vaginal progesterone: A cohort study

OBJECTIVE

To compare the hypertensive disorders of pregnancy (HDP) risk between vaginal and intramuscular (IM) progesterone in programmed frozen-thawed embryo transfer (FET) cycles.

METHODS

This was a retrospective cohort study at a tertiary hospital, and only women who achieved ongoing pregnancy after programmed FET between January 2018 and June 2022 were included. Women with chronic hypertension before pregnancy or with history of gestational hypertension or pre-eclampsia in previous pregnancies were excluded. All women were divided into IM progesterone or vaginal progesterone groups according to the route of progesterone supplementation. Follow-up information on obstetric complications and neonatal outcomes were obtained by telephonic interviews. The primary outcome was HDP. Association between routes of progesterone supplementation and HDP was assessed by subgroup analysis and multivariable logistic regression.

RESULTS

A total of 5891 programmed FET cycles (3196 IM progesterone cycles and 2695 vaginal progesterone cycles) were included in the analysis. The prevalence of HDP in the IM progesterone group was significantly lower than that of the vaginal progesterone group (6.54% vs 9.17%, P < 0.001). Therein, the prevalence of gestational hypertension (3.57% vs 4.94%, P = 0.009) and pre-eclampsia (2.97% vs 4.23%, P = 0.009) in the IM progesterone group were all significantly lower as compared to the vaginal progesterone group. According to subgroup analysis, IM progesterone was associated with lower HDP risk in all subgroups. The logistic regression analysis showed that the IM progesterone cycles were associated with lower risk of HDP compared to vaginal progesterone cycles (adjusted odds ratio 0.66, 95% CI: 0.54-0.80, P < 0.001).

CONCLUSION

Among women undergoing programmed FET cycles, progesterone supplementation with IM progesterone was associated with reduced HDP risk compared to vaginal progesterone.

Current Ovulation and Luteal Phase Tracking Methods and Technologies for Fertility and Family Planning: A Review

Ovulation is critical for both conception and overall health, but many people who may ovulate are not tracking ovulation or any other part of their menstrual cycle. Failure to track ovulation, especially in those trying to conceive, can lead to fertility challenges due to absent ovulation, mistiming intercourse, or an undetected luteal phase defect. Ovulatory disorders and mistiming intercourse are both primary causes of infertility, and tracking ovulation is shown to decrease the average time to conception. While there are many tracking methods and apps available, the majority are predictive apps or ovulation predictor kits and do not test or track both successful ovulation and the health of the luteal phase, leading to missing information that could contribute to diagnosis or successful conception. Here, we review why ovulation tracking and a healthy luteal phase are important for those trying to conceive. We present currently available ovulation tracking methods that detect both ovulation and the luteal phase, including cervical mucus, urinary hormone testing, and basal body temperature, and discuss the use, advantages, and disadvantages of each. Finally, we consider the role of digital applications and tracking technologies in ovulation tracking.

Impact of a hypocaloric dietary intervention on antral follicle dynamics in eumenorrheic women with obesity

STUDY QUESTION

Do antral follicle dynamics change in women with obesity and regular ovulatory cycles after a 6-month hypocaloric dietary intervention?

SUMMARY ANSWER

After a 6-month hypocaloric dietary intervention, women with obesity and regular ovulatory cycles displayed evidence of improved antral follicle dynamics defined by the emergence of more dominant follicles, larger ovulatory follicle diameter at selection, and increased luteal progesterone concentrations compared to pre-intervention.

WHAT IS KNOWN ALREADY

Precise events in antral folliculogenesis must occur in order for natural and regular monthly ovulation. In healthy women of reproductive age, antral follicles are recruited for growth in a wave-like fashion, wherein a subset of follicles are selected for preferential growth, and typically, one dominant follicle culminates in ovulation. Women with obesity and regular ovulatory cycles display evidence of suppressed antral follicle development, as evidenced by fewer recruitment events, fewer selectable and dominant follicles, smaller diameter of the ovulatory follicle at selection, and a higher prevalence of luteal phase defects. While improvements in gonadotropin and ovarian steroid hormone concentrations after weight loss have been documented in eumenorrheic women with obesity, the precise impact of weight loss on antral follicle dynamics has not been evaluated.

STUDY DESIGN, SIZE, DURATION

A pre-post pilot study of 12 women who participated in a 6-month hypocaloric dietary intervention.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Twelve women with obesity (total body fat ≥35%) underwent transvaginal ultrasonography and venipuncture every-other-day for one inter-ovulatory interval (IOI) both before (baseline) and during the final month (Month 7) of a six-month hypocaloric dietary intervention. Participants were aged 24-34 years and had a self-reported history of regular menstrual cycles (25-35 days). Follicle number and diameter (≥2 mm) were quantified at each study visit, and individual growth profiles for all follicles ≥7 mm were determined. Blood samples were assayed for reproductive hormones. Follicle dynamics and reproductive hormone concentrations were compared pre- and post-intervention. Further, post-intervention follicle and endocrine dynamics (Month 7 IOI) were compared to an age-matched reference cohort of lean women with regular ovulatory cycles (total body fat <35%, N = 21).

MAIN RESULTS AND THE ROLE OF CHANCE

Participants lost an average of 11% of their original body weight with the hypocaloric dietary intervention. More dominant follicles were detected (≥10 mm) at Month 7 compared to baseline (0. 3 ± 0.4 versus 0.4 ± 0.5 follicles, P = 0.001), and ovulatory follicles were selected at larger diameters post-intervention (7.3 ± 2.0 versus 10.9 ± 2.6 mm, P = 0.007). Luteal progesterone concentrations were increased at Month 7 compared to baseline (5.3 ± 3.65 versus 6.3 ± 4.74 ng/ml, P < 0.0001). However, risk for luteal phase dysfunction as judged by the prevalence of a luteal phase length <10 days, integrated luteal progesterone levels <80 ng/ml or peak progesterone <10 ng/ml did not differ pre- versus post-intervention (all, P > 0.05). In Month 7, follicle dynamics and endocrine profiles were similar to the reference cohort across all measures.

LIMITATIONS, REASONS FOR CAUTION

This study does not inform on the earliest stages of ovarian follicle development and is limited to providing knowledge on the later stages of antral follicle development. This study cannot fully address causation between weight loss and sustained improvements in antral follicle dynamics. The data cannot be extrapolated to comment on potential improvements in fertility and fecundity with weight loss. The small group sizes limit statistical power.

WIDER IMPLICATIONS OF THE FINDINGS

The increasing prevalence of obesity necessitates an understanding of the mechanisms that underlie potential improvements in reproductive health outcomes with weight loss. Women with obesity and regular ovulatory cycles who undertook a 6-month hypocaloric dietary intervention demonstrated improvements consistent with benefits of lifestyle intervention on reproductive health even in those without overt signs of reproductive dysfunction. Potential improvements in the cellular makeup of follicles, which may underlie the restoration of normal follicle development and amelioration of subfertility, require further investigation.

STUDY FUNDING/COMPETING INTEREST(S)

Cornell University, President's Council of Cornell Women, United States Department of Agriculture (Grant No. 8106), and National Institutes of Health (R01-HD0937848). B.Y.J. and H.V.B. were supported by doctoral training awards from the National Institutes of Health (T32-DK007158) and Canadian Institutes of Health Research (Grant No. 146182), respectively. The authors have no competing interests.

TRIAL REGISTRATION NUMBER

NCT01927432 and NCT01785719.

Luteal phase support in assisted reproductive technology

Infertility affects one in six couples, with in vitro fertilization (IVF) offering many the chance of conception. Compared to the solitary oocyte produced during the natural menstrual cycle, the supraphysiological ovarian stimulation needed to produce multiple oocytes during IVF results in a dysfunctional luteal phase that can be insufficient to support implantation and maintain pregnancy. Consequently, hormonal supplementation with luteal phase support, principally exogenous progesterone, is used to optimize pregnancy rates; however, luteal phase support remains largely 'black-box' with insufficient clarity regarding the optimal timing, dosing, route and duration of treatment. Herein, we review the evidence on luteal phase support and highlight remaining uncertainties and future research directions. Specifically, we outline the physiological luteal phase, which is regulated by progesterone from the corpus luteum, and evaluate how it is altered by the supraphysiological ovarian stimulation used during IVF. Additionally, we describe the effects of the hormonal triggers used to mature oocytes on the degree of luteal phase support required. We explain the histological transformation of the endometrium during the luteal phase and evaluate markers of endometrial receptivity that attempt to identify the 'window of implantation'. We also cover progesterone receptor signalling, circulating progesterone levels associated with implantation, and the pharmacokinetics of available progesterone formulations to inform the design of luteal phase support regimens.

Luteal Phase Defects and Progesterone Supplementation

Importance

Luteal phase defects (LPDs), or an insufficiency of progesterone production during the luteal phase of the menstrual cycle, have been identified as a potential cause of recurrent pregnancy loss (RPL), but its exact contribution to RPL is not well-defined. In addition, the role of exogenous progesterone supplementation during pregnancy remains controversial.

Objective

The goal of this review is to provide an updated, evidence-based summary of LPD, including prevalence and potential pathophysiologic mechanisms, and to explore the current controversies regarding progesterone supplementation for management and treatment of RPL.

Evidence Acquisition

A literature review identified relevant research using a PubMed search, Cochrane summaries, review articles, textbook chapters, databases, and society guidelines.

Results

Endogenous progesterone plays a crucial role in the first trimester of pregnancy, and therefore, insufficiency may contribute to RPL. However, the precise relationship between LPD and RPL remains unclear. Luteal phase defect is primarily a clinical diagnosis based on a luteal phase less than 10 days. Although there may be a possibility of incorporating a combined clinical and biochemical approach in defining LPD, the current lack of validated diagnostic criteria creates a challenge for its routine incorporation in the workup of infertility. Moreover, no treatment modality has demonstrated efficacy in improving fertility outcomes for LPD patients, including progesterone supplementation, whose inconsistent data do not sufficiently support its routine use, despite its minimal risk. It is imperative that women diagnosed with LPD should be worked up for other potential conditions that may contribute to a shortened luteal phase. Future work needs to focus on identifying a reproducible diagnostic test for LPD to guide treatment.

Conclusions and Relevance

Currently, the perceived relationship between LPD and RPL is challenged by conflicting data. Therefore, patients with an abnormal luteal phase should undergo a thorough workup to address any other potential etiologies. Although supplemental progesterone is commonly utilized for treatment of LPD and RPL, inconsistent supporting data call for exogenous hormone therapy to be only used in a research setting or after a thorough discussion of its shortcomings.

Progesterone and Its Metabolites Play a Beneficial Role in Affect Regulation in the Female Brain

Premenstrual dysphoric disorder is a female affective disorder that is defined by mood symptoms. The condition is linked to unstable progesterone concentrations. Progestin supplementation is given in cases of threatened or recurrent miscarriage and for luteal phase support. Progesterone is essential for implantation, immune tolerance, and modulation of uterine contractility. For a long time, the administration of progestins was associated with an unfavorable impact on mood, leading to negative affect, and, therefore, was contraindicated in existing mood disorders. Establishing the role of the natural progesterone derivative allopregnanolone in advances in the treatment of postpartum depression has shed new light on the general pathophysiology of mood disorders. Allopregnanolone directly interacts with gamma-aminobutyric acid type A (GABA-A) receptors even at nanomolar concentrations and induces significant anti-depressant, anti-stress, sedative, and anxiolytic effects. Postpartum depression is caused by a rapid drop in hormones and can be instantly reversed by the administration of allopregnanolone. Premenstrual dysphoric disorder can also be considered to result from insufficient neuroactive steroid action due to low progesterone derivative concentration, unstable hormone levels, or decreased receptor sensitivity. The decrease in progesterone levels in perimenopause is also associated with affective symptoms and an exacerbation of some psychosomatic syndromes. Bioidentical progesterone supplementation encounters several obstacles, including limited absorption, first-pass effect, and rapid metabolism. Hence, non-bioidentical progestins with better bioavailability were widely applied. The paradoxical, unfavorable effect of progestins on mood can be explained by the fact that progestins suppress ovulation and disturb the endocrine function of the ovary in the luteal phase. Moreover, their distinct chemical structure prevents their metabolism to neuroactive, mood-improving derivatives. A new understanding of progesterone-related mood disorders can translate the study results from case series and observational studies to cohort studies, clinical trials, and novel, effective treatment protocols being developed.

Serum progesterone level in luteal phase improves pregnancy rate in fresh cycles with blastocyst embryo transfer

OBJECTIVE

To assess the association between serum level of progesterone during stimulation and in the luteal phase with pregnancy rate in a cohort of patients undergoing in vitro fertilization and embryo transfer (IVF-ET) on day 5.

METHODS

Retrospective Cohort Study. Patients: 62 infertile women, aged 24-42 years, undergoing ART at our center from May 2019 to May 2021. Progesterone was evaluated during ovarian stimulation on Day 2, Day 6, and Day 8 of stimulation, day of trigger (P4dhCG), and on the day of blastocyst transfer with 5 days of progesterone supplementation (P4d5+). We also calculated the difference of P4d5+ with P4dhCG. (∆P4). Then we divided the patients into two groups based on progesterone serum levels at P4d5+; <10ng/ml (Group A), ≥10ng/ml (Group B). The Student's t-test was performed for continuous variables; Mann-Whitney's Test and Spearman's Test were used where appropriate for categorical variables. p<0.05 was considered statistically significant.

RESULTS

There were positive correlations between βhCG positive with P4d5+ (p<0.001; Rho 0.770) and ∆P4 (p<0.001; Rho 0.703). The pregnancy rate doubled when the serum progesterone level was ≥10ng/ml on the fifth day of progesterone supplementation compared with P4<10ng/ml (44% vs. 21%, respectively).

CONCLUSIONS

The pregnancy rate was positively correlated with the serum P4 level on the fifth day of progesterone supplementation and with the difference between the serum progesterone level in the Dd5+ / dhCG. A higher pregnancy rate was observed when serum progesterone level on the fifth day of progesterone supplementation was ≥10ng/ml.

Distinct urinary progesterone metabolite profiles during the luteal phase

OBJECTIVES

During normal menstrual cycles, serum levels of progesterone vary widely between cycles of same woman and between women. This study investigated the profiles of pregnanediol during the luteal phase.

METHODS

Data stemmed from a previous multicenter prospective observational study and concerned 107 women (who contributed 326 menstrual cycles). The study analyzed changes in observed cervical mucus discharge, various hormones in first morning urine, and serum progesterone. Transvaginal ultrasonography and cervical mucus helped identifying the day of ovulation. Changes in pregnanediol glucuronide levels during the luteal phase were examined and classified according to the length of that phase, a location parameter, and a scale parameter. Associations between nine pregnanediol glucuronide profiles and other hormone profiles were examined.

RESULTS

Low periovulatory pregnanediol glucuronide levels and low periovulatory luteinizing hormone levels were associated with delayed increases in pregnanediol glucuronide after ovulation. That 'delayed increase profile' was more frequently associated with cycles with prolonged high LH levels than in cycles with rapid pregnanediol glucuronide increases. A 'plateau-like profile' during the luteal phase was associated with longer cycles, cycles with higher estrone-3-glucuronide and pregnanediol glucuronide during the preovulatory phase, and cycles with higher periovulatory pregnanediol glucuronide levels.

CONCLUSIONS

Distinct profiles of urinary progesterone levels are displayed during the luteal phase. These profiles relate to early hormone changes during the menstrual cycle. In everyday clinical practice, these findings provide further evidence for recommending progesterone test seven days after the mucus peak day. The search for other correlations and associations is underway.

Progesterone: The Key Factor of the Beginning of Life

Progesterone is the ovarian steroid produced by the granulosa cells of follicles after the LH peak at mid-cycle. Its role is to sustain embryo endometrial implantation and ongoing pregnancy. Other biological effects of progesterone may exert a protective function in supporting pregnancy up to birth. Luteal phase support (LPS) with progesterone is the standard of care for assisted reproductive technology. Progesterone vaginal administration is currently the most widely used treatment for LPS. Physicians and patients have been reluctant to change an administration route that has proven to be effective. However, some questions remain open, namely the need for LPS in fresh and frozen embryo transfer, the route of administration, the optimal duration of LPS, dosage, and the benefit of combination therapies. The aim of this review is to provide an overview of the uterine and extra-uterine effects of progesterone that may play a role in embryo implantation and pregnancy, and to discuss the advantages of the use of progesterone for LPS in the context of Good Medical Practice.

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.

Vaginal progesterone as luteal phase support in natural cycle frozen-thawed embryo transfer (ProFET): protocol for a multicentre, open-label, randomised controlled trial

INTRODUCTION

Vaginal progesterone supplementation is frequently given to patients receiving frozen embryo transfer (FET) in the natural cycle aiming to increase the chance of pregnancy and live birth. To date, only a few studies have investigated if progesterone supplementation is beneficial in these cycles and the level of evidence for progesterone supplementation is very low.

METHODS AND ANALYSIS

The ProFET trial is a multicentre, open-label, randomised controlled trial powered for this investigation, including 1800 women with regular menstrual cycles (24-35 days), aged 18-43 years planned for natural cycle-FET receiving a single blastocyst for transfer. Participants are randomised (1:1:1) to either luteal phase progesterone for 3 weeks, luteal phase progesterone for 7 weeks or no luteal phase progesterone. The participating study centres consist of 12 in vitro fertilisation-clinics in Sweden and 1 in Iceland. The primary outcome is to investigate if luteal phase support (LPS) by vaginal progesterone increases the chance of a live birth per randomised patient in a natural FET cycle compared with no LPS.

ETHICS AND DISSEMINATION

The trial was approved by the Swedish Ethical Review Authority (ID 2020-06774, 2021-02822 and 2022-01502-02) and the Swedish Medical Products Agency (ID nr 5.1-2020-102613). All participants are required to provide written informed consent. The outcome of this study will be disseminated to the public through broadcasts, newspapers and presentations at scientific congresses as well as publications in international scientific journals.

TRIAL REGISTRATION NUMBER

NCT04725864.

Effectiveness of progesterone supplementation in women presenting low progesterone levels on the day of frozen embryo transfer: a randomised controlled trial

INTRODUCTION

Progesterone is an essential hormone involved in the process of implantation and pregnancy maintenance. Evidence from recent studies has supported the importance of serum progesterone level around the time of embryo transfer in hormonal replacement therapy frozen embryo transfer cycles and recommended the need for individualised luteal support. Low progesterone around the time of embryo transfer is found to be associated with decreased rate of pregnancy after frozen embryo transfer. This single-centre, longitudinal, randomised, interventional controlled study aims to compare the rate of ongoing pregnancy between two groups of women with progesterone level below 10 ng/mL on the day of frozen embryo transfer: the study group using 800 mg vaginal micronised progesterone supplemented with 50 mg intramuscular progesterone per day and the control group using only 800 mg vaginal micronised progesterone.

METHODS AND ANALYSIS

We enrol patients who are undergoing frozen embryo transfers with blastocyst-stage or cleavage-stage embryos and who satisfy the inclusion and exclusion criteria. After signing the informed consent, participants are randomised into two groups: the study group using vaginal micronised progesterone supplemented with progesterone intramuscular 50 mg per day and the control group using only vaginal micronised progesterone. Randomisation will be performed using R software at a 1:1 allocation ratio. Sequentially numbered, opaque sealed envelopes are used for allocation. The primary outcome is the rate of ongoing pregnancy. To demonstrate a difference of 10% with regard to rate of ongoing pregnancy, at least 370 participants per arm are required (type I error α=0.05, power=0.8). Assuming a dropout rate of 10%, a total of 824 patients (412 per group) will be invited.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of Tu Du Hospital on 17 May 2021 (reference number: 1251/QĐ-BVTD). All participants provide informed consent before being enrolled in the study. The results of our study will be submitted to reproductive medicine conferences and journals.

TRIAL REGISTRATION NUMBER

NCT04897269.

The efficacy and safety of luteal phase support with progesterone following ovarian stimulation and intrauterine insemination: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to update the current evidence for the efficacy and safety of progesterone luteal phase support (LPS) following ovarian stimulation and intrauterine insemination treatment (OS-IUI) for unexplained or mild male infertility. Four additional studies were identified compared to the previous review in 2017. Twelve RCTs (2631 patients, 3262 cycles) met full inclusion criteria. Results from quantitative synthesis suggest that progesterone LPS after OS-IUI leads to higher live birth (RR 1.38, 95%CI [1.09, 1.74]; 7 RCTs, n=1748) and clinical pregnancy rates (RR 1.38, 95% CI [1.21, 1.59]; 11 RCTs, n=2163) than no LPS or placebo. This effect is specifically present in protocols using gonadotropins for OS-IUI (RR 1.41, 95%CI [1.17, 1.71]; 7 RCTs, n=1114), and unclear in protocols involving clomiphene citrate (RR 1.01, 95% CI [0.05, 18.94]; 2 RCTs, n=138). We found no effect of progesterone LPS on multiple pregnancy or miscarriage rates. No correlation between drug-dosage or duration of treatment and effect size was seen. Though our results suggest both benefit and safety of progesterone LPS in OS-IUI, evidence is of low to moderate quality and additional well-powered trials are still mandatory to confirm our findings and justify implementation in daily practice.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=292325, identifier CRD42021292325.

Serum luteal phase progesterone in women undergoing frozen embryo transfer in assisted conception: a systematic review and meta-analysis

OBJECTIVE

To investigate the association between luteal serum progesterone levels and frozen embryo transfer (FET) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Women undergoing FET.

INTERVENTION(S)

We conducted electronic searches of MEDLINE, PubMed, CINAHL, EMBASE, the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and grey literature (not widely available) from inception to March 2021 to identify cohort studies in which the serum luteal progesterone level was measured around the time of FET.

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy or live birth rate, clinical pregnancy rate, and miscarriage rate.

RESULT(S)

Among the studies analyzing serum progesterone level thresholds <10 ng/mL, a higher serum progesterone level was associated with increased rates of ongoing pregnancy or live birth (relative risk [RR] 1.47, 95% confidence interval [CI] 1.28 to 1.70), higher chance of clinical pregnancy (RR 1.31, 95% CI 1.16 to 1.49), and lower risk of miscarriage (RR 0.62, 95% CI 0.50 to 0.77) in cycles using exclusively vaginal progesterone and blastocyst embryos. There was uncertainty about whether progesterone thresholds ≥10 ng/mL were associated with FET outcomes in sensitivity analyses including all studies, owing to high interstudy heterogeneity and wide CIs.

CONCLUSION(S)

Our findings indicate that there may be a minimum clinically important luteal serum concentration of progesterone required to ensure an optimal endocrine milieu during embryo implantation and early pregnancy after FET treatment. Future clinical trials are required to assess whether administering higher-dose luteal phase support improves outcomes in women with a low serum progesterone level at the time of FET.

PROSPERO NUMBER

CRD42019157071.

Impact of Plasmatic Progesterone on the Day of Frozen Embryo Transfer in Hormone-induced Cycles

OBJECTIVE

 To establish a relationship between serum progesterone values on the day of frozen blastocyst transfer in hormone-replaced cycles with the probability of pregnancy, miscarriage or delivery.

METHODS

 This was an ambispective observational study including all frozen-thawed embryo transfer cycles performed at our department following in vitro fecundation from May 2018 to June 2019. The outcomes evaluated were β human chorionic gonadotropin (β-hCG)-positive pregnancy and delivery. Groups were compared according to the level of serum progesterone on the day of embryo transfer: the 1st quartile of progesterone was compared against the other quartiles and then the 2nd and 3rd quartiles against the 4th quartile.

RESULTS

 A total of 140 transfers were included in the analysis: 87 with β-HCG > 10 IU/L (62%), of which 50 (36%) delivered and 37 had a miscarriage (42%). Women with lower progesterone levels (< 10.7ng/mL) had a trend toward higher β-HCG-positive (72 versus 59%; p > 0.05), lower delivery (26 versus 39%; p > 0.05) and higher miscarriage rates (64 versus 33%; p < 0.01). Comparing the middle quartiles (P25-50) with those above percentiles 75, the rate of pregnancy was similar (60 versus 57%; p > 0.05), although there was a trend toward a higher number of deliveries (43 versus 31%; p > 0.05) and a lower number of miscarriages (28 versus 45%; p > 0.05). These differences were not statistically significant.

CONCLUSION

 There were no differences in pregnancy and delivery rates related with the progesterone level when measured in the transfer day. The miscarriage rate was higher in the 1st quartile group.

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.

New concepts and difficulties with progesterone supplementation in the luteal phase

PURPOSE OF REVIEW

Management of the luteal phase (LP) in assisted reproductive cycles has aroused interest in recent years. The reason is that it seems that the individualization of LP support may be necessary, since the concept of 'one size fits all' does not apply to this treatment.

RECENT FINDINGS

Studies carried out in hormone replacement therapy cycles (also called artificial cycles) have shown that serum levels of progesterone (P) are related to pregnancy outcomes. This represents a milestone in the management of artificial cycles (AC), because until a few years ago it was believed that serum levels did not really reflect the effectiveness of P, which is why they were neglected. However, it is not as straightforward as it seems, because the interpretation of serum progesterone values will depend on the type of progesterone used and its route of administration. Likewise, the findings observed in AC are not applicable to what occurs in a fresh transfer cycle after ovarian stimulation or an embryo transfer in the context of a natural cycle.

SUMMARY

In this manuscript, we will summarize the current situation in LP management.

Individualised luteal phase support in artificially prepared frozen embryo transfer cycles based on serum progesterone levels: a prospective cohort study

STUDY QUESTION

Does an individualised luteal phase support (iLPS), according to serum progesterone (P4) level the day prior to euploid frozen embryo transfer (FET), improve pregnancy outcomes when started on the day previous to embryo transfer?

SUMMARY ANSWER

Patients with low serum P4 the day prior to euploid FET can benefit from the addition of daily subcutaneous P4 injections (Psc), when started the day prior to FET, and achieve similar reproductive outcomes compared to those with initial adequate P4 levels.

WHAT IS KNOWN ALREADY

The ratio between FET/IVF has spectacularly increased in the last years mainly thanks to the pursuit of an ovarian hyperstimulation syndrome free clinic and the development of preimplantation genetic testing (PGT). There is currently a big concern regarding the endometrial preparation for FET, especially in relation to serum P4 levels around the time of embryo transfer. Several studies have described impaired pregnancy outcomes in those patients with low P4 levels around the time of FET, considering 10 ng/ml as one of the most accepted reference values. To date, no prospective study has been designed to compare the reproductive outcomes between patients with adequate P4 the day previous to euploid FET and those with low, but restored P4 levels on the transfer day after iLPS through daily Psc started on the day previous to FET.

STUDY DESIGN, SIZE, DURATION

A prospective observational study was conducted at a university-affiliated fertility centre between November 2018 and January 2020 in patients undergoing PGT for aneuploidies (PGT-A) IVF cycles and a subsequent FET under hormone replacement treatment (HRT). A total of 574 cycles (453 patients) were analysed: 348 cycles (leading to 342 euploid FET) with adequate P4 on the day previous to FET, and 226 cycles (leading to 220 euploid FET) under iLPS after low P4 on the previous day to FET, but restored P4 levels on the transfer day.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall we included 574 HRT FET cycles (453 patients). Standard HRT was used for endometrial preparation. P4 levels were measured the day previous to euploid FET. P4 > 10.6 ng/ml was considered as adequate and euploid FET was performed on the following day (FET Group 1). P4 < 10.6 ng/ml was considered as low, iLPS was added in the form of daily Psc injections, and a new P4 analysis was performed on the following day. FET was only performed on the same day when a restored P4 > 10.6 ng/ml was achieved (98.2% of cases) (FET Group 2).

MAIN RESULTS AND THE ROLE OF CHANCE

Patient's demographics and cycle parameters were comparable between both euploid FET groups (FET Group 1 and FET Group 2) in terms of age, weight, oestradiol and P4 levels and number of embryos transferred. No statistically significant differences were found in terms of clinical pregnancy rate (56.4% vs 59.1%: rate difference (RD) -2.7%, 95% CI [-11.4; 6.0]), ongoing pregnancy rate (49.4% vs 53.6%: RD -4.2%, 95% CI [-13.1; 4.7]) or live birth rate (49.1% vs 52.3%: RD -3.2%, 95% CI [-12; 5.7]). No significant differences were also found according to miscarriage rate (12.4% vs 9.2%: RD 3.2%, 95% CI [-4.3; 10.7]).

LIMITATIONS, REASONS FOR CAUTION

Only iLPS through daily Psc was evaluated. The time for Psc injection was not stated and no serum P4 determinations were performed once the pregnancy was achieved.

WIDER IMPLICATIONS OF THE FINDINGS

Our study provides information regarding an 'opportunity window' for improved ongoing pregnancy rates and miscarriage rates through a daily Psc injection in cases of inadequate P4 levels the day previous to FET (P4 < 10.6 ng/ml) and restored values the day of FET (P4 > 10.6 ng/ml). Only euploid FET under HRT were considered, avoiding one of the main reasons of miscarriage and implantation failure and overcoming confounding factors such as female age, embryo quality or ovarian stimulation protocols.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received. B.C. reports personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, IBSA and Gedeon Richter outside the submitted work. N.P. reports grants and personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, Theramex and Besins International and personal fees from IBSA and Gedeon Richter outside the submitted work. The remaining authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NCT03740568.

Evaluating the influence of progesterone concentration and time of exposure on in vitro endometrial decidualisation

This study aimed to evaluate the influence of progesterone (concentration and time of exposure) on endometrial decidualisation using an in vitro model cell line: Human Endometrial Stromal Cells (HESCs). HESCs exposed to progesterone (1 and 10 μM) had higher percentages of decidualised cells and higher expression of the decidual marker (Insulin Like Growth Factor Binding Protein 1 (IGFBP1)) compared with those exposed to (0.1 μM). Among those HESCs cultured with 1 μM progesterone for 11 days, the highest rate of morphological differentiation (40-50%) occurred between days 7-9 and IGFBP1 peaked on day 7. The cell-cycle pathway was significantly down-regulated in HESCs exposed to at least 1 μM progesterone regardless of the incubation period. We conclude that exposure to high progesterone concentration for 7-9 days is essential to maximise the process of decidualisation.

Low progesterone levels on the day before natural cycle frozen embryo transfer are negatively associated with live birth rates

STUDY QUESTION

Are progesterone (P) levels on the day before natural cycle frozen embryo transfer (NC-FET) associated with live birth rate (LBR)?

SUMMARY ANSWER

Regular ovulatory women undergoing NC-FET with serum P levels <10 ng/ml on the day before blastocyst transfer have a significantly lower LBR than those with serum P levels >10 ng/ml.

WHAT IS KNOWN ALREADY

The importance of serum P levels around the time of embryo transfer in patients undergoing FET under artificial endometrial preparation has been well established. However, no study has analyzed the importance of serum P levels in patients undergoing FET under a true natural endometrial preparation cycle.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study including 294 frozen blastocyst transfers under natural cycle endometrial preparation at a university-affiliated fertility centre between January 2016 and January 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All patients had regular menstrual cycles and underwent NC-FET with their own oocytes. Only patients who had undergone serum P measurement between 8 am and 11 am on the day before FET were included. Patients did not receive any external medication for endometrial preparation or luteal phase support. Patients were divided into two groups according to serum P levels below or above 10 ng/ml on the day before FET. Univariate analysis was carried out to describe and compare the cycle characteristics with reproductive outcomes. To evaluate the effect of P, a multivariable logistic model was fitted for each outcome after adjusting for confounding variables.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean serum P levels on the day before FET were significantly higher in patients who had a live birth compared to those who did not (14.5 ± 7.0 vs 12.0 ± 6.6 ng/ml, 95% CI [0.83; 4.12]). The overall clinical pregnancy rate (CPR) and LBR were 42.9% and 35.4%, respectively. Patients in the higher P group (>10 ng/ml) had a higher LBR (41.1% vs 25.7%: risk difference (RD) 15.4%, 95% CI [5; 26]) and CPR (48.6% vs 33.0%: RD 15.6%, 95% CI [4; 27]). Patients with higher serum P levels on the day before FET (63% of patients) had an improved LBR (odds ratio: 1.05; 95% CI [1.02; 1.09]). Women with serum P levels <10 ng/ml on the day before FET (37% of patients) had significantly higher weights (62.5 ± 9.9 vs 58.1 ± 7.1 kg, 95% CI [1.92; 6.90]) and BMI (22.9 ± 3.6 vs 21.6 ± 2.7 kg/m2, 95% CI [0.42; 2.25]) compared to patients with P levels >10 ng/ml.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of our study is its retrospective design. Other potential limitations are the detection of LH surge through urine testing and the inclusion of patients who did and did not undergo preimplantation genetic testing for aneuploidies. The protocol used in our institution for monitoring NC-FET does not look for the onset of progesterone secretion by the corpus luteum, and a slow luteinisation process or delay of corpus luteum function cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

We provide evidence that a minimum serum P threshold (P >10 ng/ml) might be required for improved reproductive outcomes in NC-FET. This result suggests that there are different mechanisms by which P is produced and/or distributed by each patient. This study also provides an excellent model to evaluate the impact of luteal phase defect through NC-FET. A prospective evaluation to assess whether P supplementation should be individualised according to patient's needs is necessary to support our findings.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used, and there are no competing interests.

Recurrent Spontaneous Miscarriage: a Comparison of International Guidelines

While roughly 30% of all women experience a spontaneous miscarriage in their lifetime, the incidence of recurrent (habitual) spontaneous miscarriage is 1 – 3% depending on the employed definition. The established risk factors include endocrine, anatomical, infection-related, genetic, haemostasis-related and immunological factors. Diagnosis is made more difficult by the sometimes diverging recommendations of the respective international specialist societies. The present study is therefore intended to provide a comparison of existing international guidelines and recommendations. The guidelines of the ESHRE, ASRM, the DGGG/OEGGG/SGGG and the recommendations of the RCOG were analysed. It was shown that investigation is indicated after 2 clinical pregnancies and the diagnosis should be made using a standardised timetable that includes the most frequent causes of spontaneous miscarriage. The guidelines concur that anatomical malformations, antiphospholipid syndrome and thyroid dysfunction should be excluded. Moreover, the guidelines recommend carrying out pre-conception chromosomal analysis of both partners (or of the aborted material). Other risk factors have not been included in the recommendations by all specialist societies, on the one hand because of a lack of diagnostic criteria (luteal phase insufficiency) and on the other hand because of the different age of the guidelines (chronic endometritis). In addition, various economic and consensus aspects in producing the guidelines influence the individual recommendations. An understanding of the underlying decision-making process should lead in practice to the best individual diagnosis and resulting treatment being offered to each couple.

Non-Coding RNAs Regulate Placental Trophoblast Function and Participate in Recurrent Abortion

Recurrent spontaneous abortion (RSA) is a serious pregnancy complication with an increasing clinical incidence. The various causes of recurrent abortion are complicated. Developments in genetics, immunology, and cell biology have identified important roles of non-coding RNAs (ncRNAs) in the occurrence and progress of recurrent abortion. NcRNAs can affect the growth, migration, and invasion of placental trophoblasts by regulating cell processes such as the cell cycle, apoptosis, and epithelial-mesenchymal transformation. Therefore, their abnormal expression might lead to the occurrence and development of RSA. NcRNAs include small nuclear RNA (snRNA), small nucleolar RNA (snoRNA), ribosomal RNA (rRNA), transfer, RNA (tRNA), circular RNA (cRNA), and Piwi-interacting RNA (piRNA). In this review, we discuss recent research that focused on the function and mechanism of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNA (circRNA) in regulating placental trophoblasts. The use of ncRNAs as potential diagnostic and predictive biomarkers in RSA is also discussed to provide future research insights.

Multiple-dose versus single-dose gonadotropin-releasing hormone agonist after first in vitro fertilization failure associated with luteal phase deficiency: A randomized controlled trial

Objective

To evaluate the efficacy and safety of multiple- versus single-dose gonadotropin-releasing hormone agonist (GnRH-a) addition to luteal phase support (LPS), in patients with a first in vitro fertilization (IVF) failure associated with luteal phase deficiency (LPD).

Methods

Eighty patients with a first IVF failure associated with LPD were randomly assigned into single-dose and multiple-dose GnRH-a groups. In the second IVF attempt, patients in the single-dose group were given standard LPS plus a single dose of GnRH-a 6 days after oocyte retrieval. Patients in the multiple-dose group received standard LPS plus 14 daily injections of GnRH-a. Children conceived were followed up for 2 years.

Results

Pregnancy (67.5% vs. 42.5%), clinical pregnancy (50.0% vs. 22.5%), and live birth rates (42.5% vs. 20.0%) were significantly higher in the multiple-dose versus single-dose GnRH-a group. Patients in the multiple-dose GnRH-a group had significantly higher progesterone levels 14 days after oocyte recovery (35.9 vs. 21.4 ng/mL). No significant difference existed in the status at birth or developmental and behavior assessments of 2-year-old children conceived in both groups.

Conclusions

Daily addition of GnRH-a to standard LPS can achieve better pregnancy outcomes with a sustained safety profile in patients with a first IVF failure associated with LPD.

Diagnosis and treatment of luteal phase deficiency: a committee opinion

Luteal phase deficiency (LPD) is a clinical diagnosis associated with an abnormal luteal phase length of ≤10 days. Potential etiologies of LPD include inadequate progesterone duration, inadequate progesterone levels, or endometrial progesterone resistance. LPD has not only been described in association with medical conditions but also in fertile, normally menstruating women. Although progesterone is important for the process of implantation and early embryonic development, LPD has not been proven to be an independent entity causing infertility or recurrent pregnancy loss. Controversy exists regarding the multiple proposed measures for diagnosing LPD and, assuming it can be diagnosed accurately, whether treatment improves outcomes. This document replaces the document entitled "Current clinical irrelevance of luteal phase deficiency: a committee opinion," last published in 2015 (Fertil Steril 2015;103:e27-e32).

Women utilizing oocyte donation have a decreased live birth rate if they displayed a low progesterone level in a previous hormonal replacement mock cycle

PURPOSE

Is serum progesterone(P) level on day 2 of vaginal P administration in a hormonally substituted mock cycle predictive of live birth in oocyte donation(OD)?

METHODS

Retrospective analysis of 110 mock cycles from 2008 to 2016 of OD recipients having at least one subsequent embryo transfer (ET). Endometrial preparation consisted of sequential administration of vaginal estradiol, followed by transdermal estradiol and 600 mg/day vaginal micronized P. In mock cycles, serum P was measured 2 days after vaginal P introduction. OD was performed 1 to 3 years later, without P measurement.

RESULTS

In mock cycles, mean serum P level on day 2 was 12.8 ± 4.5 ng/mL (range: 4-28 ng/mL). A total of 32% patients had P < 10 ng/mL. At the time of first OD, age of recipients and donors, number of retrieved and attributed oocytes, and number of transferred embryos were comparable between patients with P < 10 ng/mL in their mock cycles compared with P ≥ 10 ng/mL. Pregnancy and live birth rate after first ET were significantly lower for patients with P < 10ng/mL (9% vs. 35 %; P = 0.002 and 9% vs. 32%; P = 0.008, respectively). Considering both fresh and subsequent frozen-thawed ET, cumulative live birth rate per-patient and per-transfer were significantly lower in patients with P < 10 ng/mL in their mock cycle (14% vs. 35%; P = 0.02 and 11% vs. 27%; P = 0.03).

CONCLUSION

A low P level in hormonally substituted cycles several years before ET performed with the same endometrial preparation is associated with a significantly lower chance of live birth. This suggests that altered vaginal P absorption is a permanent phenomenon. Monitoring serum P in hormonally substituted cycles appears mandatory to adjust luteal P substitution.

Triglyceride Induced Metabolic Inflammation: Potential Connection of Insulin Resistance and Recurrent Pregnancy Loss

The underlying correlative mechanisms between Insulin resistance (IR) and recurrent pregnancy loss (RPL) in patients without polycystic ovarian syndrome (PCOS) remain inconclusive. To investigate the association between triglyceride (TG) levels, lymphocyte subsets, and IR in RPL patients without PCOS and obesity. Eighty-nine subjects with an unexplained RPL, independent of PCOS/obesity were enrolled in this study. A 75-g oral glucose tolerance test was performed on each subject with plasma tested for glucose and insulin. The fasting venous blood of all subjects was collected for routine clinical chemistry analysis. Lymphocyte subsets were analyzed by four-color flow cytometry. As a result, TG levels were significantly elevated in RPL patients with IR compared to those without IR. Pearson linear correlation model and receiver operating characteristic (ROC) curve analyses revealed a significant positive association between TG and HOMA-IR index value. In multiple logistic regression analysis, TG was significantly associated with the risk of hyperinsulinemia and increased CD3⁺CD4⁺/CD3⁺CD8⁺ ratio which was significantly negatively correlated with disposition index (DI30) and DI120, indicators for insulin sensitivity. In addition, DI30 and DI120 were significantly decreased in the higher CD3⁺CD4⁺/CD3⁺CD8⁺ group. Our findings showed that the elevated TG and altered immune responses in RPL patients with IR are independent of PCOS and obesity, and could be used as an indicator of IR in RPL patients. These results contribute to the understanding of the pathophysiology of IR in RPL for potential prevention and therapeutic targets.

Oral dydrogesterone vs. micronized vaginal progesterone gel for luteal phase support in frozen-thawed single blastocyst transfer in good prognosis patients

OBJECTIVE

To investigate the efficacy of oral dydrogesterone for luteal phase support (LPS) in modified natural cycle frozen-thawed embryo transfers (mNC-FET) compared to micronized vaginal progesterone (MVP) gel.

METHODS

This was a randomized, single-center, parallel controlled trial conducted at an ART and Reproductive Genetics Centre within a private hospital between January and August 2019. A total of 134 women, aged below 38, were assigned randomly to receive oral dydrogesterone (n=67) or MVP (n=67) for LPS in mNC-FET. The primary outcome was ongoing pregnancy rate (OPR) and secondary outcomes were clinical pregnancy and miscarriage rates, patients' satisfaction and tolerability of oral and vaginal progesterone. A questionnaire was developed to compare patient satisfaction and side effect profiles.

RESULTS

There was no significant difference in demographic features such as female age, body mass index, AMH levels and fresh cycle characteristics between two groups (p>0.05). When mNC-FET outcomes were compared, OPR was 68.7 % in MVP gel group and 71.6 % in the dydrogesterone group respectively percentage difference, -2.99; 95 % CI: -17.96, 13.10) Biochemical and clinical pregnancy rates and biochemical and clinical miscarriage rates were also similar between two groups. A significantly higher patient tolerability score was present in the dydrogesterone arm (4.09 ± 0.96 vs 3.36 ± 1.23, p=0.001).

CONCLUSION

Our results suggest that oral dydrogesterone provides similar ongoing pregnancy rates compared to MVP gel as a LPS in mNC FET. Since dydrogesterone is an effective and easy-to-use option with fewer intolerable side effects including vaginal irritation, vaginal discharge, and preventing sexual intercourse, it can be used as LPS in mNC FET.

Suboptimal mid-luteal progesterone concentrations are associated with aberrant endometrial gene expression, potentially resulting in implantation failure

RESEARCH QUESTION

What is the difference in endometrial transcriptomics between women with normal and with low mid-luteal progesterone during the implantation window?

DESIGN

An endometrial biopsy and serum progesterone concentration were taken from participants during the mid-luteal phase (LH+7 to LH+9). A total of 12 participants were recruited and categorized into two groups based on their progesterone concentrations: normal progesterone (>15 ng/ml, n = 6) and low progesterone (<15 ng/ml, n = 6). Global endometrial gene expression between the two groups was compared by microarray techniques. Principal component analysis was used to display the gene's expression pattern. Pathway and gene ontology enrichment analysis were performed to determine the biological mechanism of progesterone on the endometrium.

RESULTS

Several key genes related to endometrial receptivity were found to be regulated by progesterone. With regard to gene ontology and pathway analysis, progesterone was shown to be mainly involved in structure morphogenesis predominantly during a process of decidualization, extracellular matrix-receptor interaction and cell adhesion. Distinct differences were observed in the transcriptomic profiles between the two groups, indicating potential impairment of endometrial receptivity in women with suboptimal progesterone concentrations. There was a relatively similar pattern of gene expression between endometrial samples with progesterone concentrations approximately 10 ng/ml and >15 ng/ml. Thus, a progesterone concentration of between 10 and 15 ng/ml appears to be sufficient to induce endometrial receptivity.

CONCLUSIONS

Abnormally low progesterone below the threshold of 10-15 ng/ml during the implantation window results in aberrant endometrial gene expression that may affect implantation potential.

Luteal phase support in fresh and frozen embryo transfer cycles

Nearly 5 million babies have been delivered following assisted conception (IVF/ICSI) and the demand is increasing. Meticulous ovarian stimulation and well programmed luteal phase support are the landmarks of treatment success. Although the importance of luteal phase support in IVF/ICSI cycles is well established, the optimal route, dose and duration of this support is still a matter of debate. Regardless of the ovarian stimulation, parenteral and vaginal progesterone has been one of the most common routes. However, oral or subcutaneous routes are also well-investigated and reveal satisfactory clinical outcomes. It is obviously critical to choose a progesterone with adequate clinical efficacy and patient tolerability as well. Moreover, fresh and frozen embryo transfer cycles markedly different from each other in terms of physiological changes and luteal support concept should be modified accordingly. The aim of this narrative review is to provide evidence-based take home messages for the luteal phase support in either fresh or frozen embryo transfer cycles in the context of a recent scientific evidence.

Progesterone use in assisted reproductive technology

Progesterone is the main hormone in the luteal phase. It plays a key role in preparing the uterus for a possible pregnancy, and in maintaining it after it has occurred. In assisted reproduction treatments, there is usually a luteal phase deficiency, so it is necessary to supplement this critical phase to obtain the best results, not only of implantation but also of ongoing pregnancy. Among all the available options, exogenously administered progestogens are the most used, as they have proven their efficacy and safety. This review will address the most relevant aspects of luteal phase support with progesterone in the different scenarios an embryo transfer can be performed, such as the stimulated cycle, the artificial cycle, or the natural cycle. Although there is no evidence of the perfect protocol for all patients, recent studies point to the need of individualizing luteal phase support according to the needs of each patient.

Characterizing physiological and symptomatic variation in menstrual cycles using self-tracked mobile-health data

The menstrual cycle is a key indicator of overall health for women of reproductive age. Previously, menstruation was primarily studied through survey results; however, as menstrual tracking mobile apps become more widely adopted, they provide an increasingly large, content-rich source of menstrual health experiences and behaviors over time. By exploring a database of user-tracked observations from the Clue app by BioWink GmbH of over 378,000 users and 4.9 million natural cycles, we show that self-reported menstrual tracker data can reveal statistically significant relationships between per-person cycle length variability and self-reported qualitative symptoms. A concern for self-tracked data is that they reflect not only physiological behaviors, but also the engagement dynamics of app users. To mitigate such potential artifacts, we develop a procedure to exclude cycles lacking user engagement, thereby allowing us to better distinguish true menstrual patterns from tracking anomalies. We uncover that women located at different ends of the menstrual variability spectrum, based on the consistency of their cycle length statistics, exhibit statistically significant differences in their cycle characteristics and symptom tracking patterns. We also find that cycle and period length statistics are stationary over the app usage timeline across the variability spectrum. The symptoms that we identify as showing statistically significant association with timing data can be useful to clinicians and users for predicting cycle variability from symptoms, or as potential health indicators for conditions like endometriosis. Our findings showcase the potential of longitudinal, high-resolution self-tracked data to improve understanding of menstruation and women's health as a whole.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Midluteal Progesterone: A Marker of Treatment Outcomes in Couples With Unexplained Infertility

CONTEXT

Adequate luteal phase progesterone exposure is necessary to induce endometrial changes required for a successful pregnancy outcome. The relationship between low midluteal progesterone concentration and the outcome of live birth in ovarian stimulation with intrauterine insemination (OS-IUI) treatments is not defined.

OBJECTIVE

To determine the level of midluteal progesterone portending a low chance of live birth after OS-IUI in couples with unexplained infertility.

DESIGN AND SETTING

Secondary analyses of data from a prospective, randomized, multicenter clinical trial that determined pregnancy outcomes following OS-IUI with clomiphene citrate, letrozole, or gonadotropins for couples with unexplained infertility.

PARTICIPANTS

Couples (n = 900) underwent 2376 OS-IUI cycles during the Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation clinical trial.

MAIN OUTCOME MEASURES

Live birth as it relates to midluteal progesterone level and thresholds below which no live births occur by treatment group.

RESULTS

Thresholds for non-live birth cycles were similar for clomiphene (14.4 ng/mL) and letrozole (13.1 ng/mL) yet were lower for gonadotropin (4.3 ng/mL) treatments. A midluteal progesterone level >10th percentile specific for each treatment group independently was associated with greater odds for a live birth in all OS-IUI cycles (adjusted OR: 2.17; 95% CI: 1.05, 4.48).

CONCLUSIONS

During OS-IUI, a low midluteal progesterone level was associated with a low probability of live birth. Thresholds differed by medication, with the lowest threshold for gonadotropin. Several pathophysiologic mechanisms may account for low progesterone levels. Refinement of the predictive range associated with particular ovarian stimulation medications during treatment of unexplained infertility may improve accuracy.

Bender Atik R, Christiansen OB, Elson J, Kolte AM, Lewis S, Middeldorp S, Nelen W, Peramo B, Quenby S, Vermeulen N, Goddijn M. ESHRE guideline: recurrent pregnancy loss

STUDY QUESTION

What is the recommended management of women with recurrent pregnancy loss (RPL) based on the best available evidence in the literature?

SUMMARY ANSWER

The guideline development group formulated 77 recommendations answering 18 key questions on investigations and treatments for RPL, and on how care should be organized.

WHAT IS KNOWN ALREADY

A previous guideline for the investigation and medical treatment of recurrent miscarriage was published in 2006 and is in need of an update.

STUDY DESIGN, SIZE, DURATION

The guideline was developed according to the structured methodology for development of ESHRE guidelines. After formulation of key questions by a group of experts, literature searches and assessments were performed. Papers published up to 31 March 2017 and written in English were included. Cumulative live birth rate, live birth rate and pregnancy loss rate (or miscarriage rate) were considered the critical outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the collected evidence, recommendations were formulated and discussed until consensus was reached within the guideline group. A stakeholder review was organized after finalization of the draft. The final version was approved by the guideline group and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

The guideline provides 38 recommendations on risk factors, prevention and investigations in couples with RPL, and 39 recommendations on treatments. These include 60 evidence-based recommendations – of which 31 were formulated as strong recommendations and 29 as conditional – and 17 good practice points. The evidence supporting investigations and treatment of couples with RPL is limited and of moderate quality. Of the evidence-based recommendations, only 10 (16.3%) were supported by moderate quality evidence. The remaining recommendations were supported by low (35 recommendations: 57.4%), or very low quality evidence (16 recommendations: 26.2%). There were no recommendations based on high quality evidence. Owing to the lack of evidence-based investigations and treatments in RPL care, the guideline also clearly mentions investigations and treatments that should not be used for couples with RPL.

LIMITATIONS, REASONS FOR CAUTION

Several investigations and treatments are offered to couples with RPL, but most of them are not well studied. For most of these investigations and treatments, a recommendation against the intervention or treatment was formulated based on insufficient evidence. Future studies may require these recommendations to be revised.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in RPL, based on the best evidence available. In addition, a list of research recommendations is provided to stimulate further studies in RPL. One of the most important consequences of the limited evidence is the absence of evidence for a definition of RPL.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive payment. J.E. reports position funding from CARE Fertility. S.L. reports position funding from SpermComet Ltd. S.M. reports research grants, consulting and speaker’s fees from GSK, BMS/Pfizer, Sanquin, Aspen, Bayer and Daiichi Sankyo. S.Q. reports speaker’s fees from Ferring. The other authors report no conflicts of interest.

ESHRE Pages are not externally peer reviewed. This article has been approved by the Executive Committee of ESHRE.

Luteal phase serum progesterone levels after GnRH-agonist trigger - how low is still high enough for an ongoing pregnancy?

In the past years, individualization of assisted reproductive technique (ART)-treatment is increasingly common to customize the treatment protocol to the patient's specific conditions. The use of GnRH-agonist for final oocyte maturation in a gonadotropin-releasing hormone (GnRH)-antagonist protocol is the best approach to reduce the risk for ovarian hyperstimulation in high responder patients. However, due to severe luteolysis, the reproductive outcome with this approach in combination with the use of vaginal progesterone as luteal phase support, was poor. Cycle segmentation as alternative to a fresh transfer requires embryo freezing which might not be applicable to all patients due to various reasons. The concept of luteal coasting monitors the progesterone-level closely and human chorionic gonadotropin (hCG) for rescue of the corpora lutea is administered when the progesterone-level drops below a certain threshold. However, the lower range of progesterone levels in the early luteal phase after GnRH-agonist trigger, which is compatible with achieving and maintaining a pregnancy, is unknown. This case-series demonstrates, that ongoing pregnancies can be achieved even with a progesterone-level below 15 ng/ml in the early luteal phase with the timely administration of an hCG-rescue bolus. With the concept of luteal coasting, individualization of the luteal phase support according to the patient's specific luteolysis pattern is possible.