Role and effectiveness of progestins in pituitary suppression during ovarian stimulation for assisted reproductive technology: a systematic review and a meta-analysis

Exposure of antral follicles to medroxyprogesterone acetate during stimulation does not cause molecular perturbations in gonadotropin-responsiveness and steroidogenic function of granulosa cells in progestin-primed cycles

STUDY QUESTION

Does medroxyprogesterone acetate (MPA) exposure in progestin-primed ovarian stimulation (PPOS) cycles cause molecular perturbations in the steroidogenic function and gonadotropin responsiveness of the granulosa cells?

SUMMARY ANSWER

PPOS cycles are identical to traditional GnRH antagonist cycles not only for clinical IVF characteristics but also for gonadotropin receptor expression, response to gonadotropins, and steroidogenic function at the molecular level.

WHAT IS KNOWN ALREADY

PPOS is increasingly used as an alternative to GnRH antagonists due to the inhibitory effect of progesterone on LH release by reducing GnRH pulsatility at the hypothalamic level. Although a growing body of evidence from clinical studies did not indicate significant differences between PPOS and antagonist protocols for IVF cycle characteristics and obstetrical outcomes, it is still unknown whether exposure of the antral follicle cohort to progesterone or its synthetic derivatives during ovarian stimulation causes any subtle molecular aberrations in terms of steroidogenesis and gonadotropin responsiveness. To address this issue, detailed comparative molecular analyses were conducted in the luteinized mural granulosa cells (GCs) obtained from normal responding IVF patients undergoing PPOS and antagonist cycles.

STUDY DESIGN, SIZE, DURATION

A clinical translational research study was conducted with IVF patients.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study included 55 normal responding IVF patients who underwent ovarian stimulation with either PPOS using MPA (5 mg twice daily) or GnRH antagonist cetrorelix acetate. Recombinant forms of FSH and hCG were used for ovarian stimulation and ovulation triggering, respectively. Luteinized mural GCs obtained during the oocyte retrieval procedure were used for the experiments. Cell culture, quantitative real-time PCR, immunoblotting, confocal time-lapse live cell imaging, and hormone assays were used.

MAIN RESULTS AND THE ROLE OF CHANCE

Demographic and IVF cycle characteristics of the patients undergoing ovarian stimulation with PPOS and GnRH antagonist were similar, including ovarian response, mature oocyte yield, and fertilization rates. Molecular analyses revealed that the expression of the enzymes involved in sex-steroid synthesis (StAR, SCC, 3β-HSD, 17β-HSD, aromatase) and the uptake/storage/utilization of cholesterol (LDL receptor, Hormone-sensitive lipase, hydroxy-methyl glutaryl Co-enzyme-A reductase, and Sterol O-acyltransferase1) in the GCs of the PPOS cycles were comparable to those of the antagonist cycles. The expression of the receptors for gonadotropins, estrogen, and progesterone hormones was also similar. Basal and hCG-induced increases in 3β-HSD expression and progesterone production and basal and FSH-induced increases in aromatase expression and E2 output of the GCs from PPOS patients did not exhibit any meaningful differences when compared with GCs from antagonist cycles. Furthermore, basal and hCG-induced up-regulation in the LDL receptor expression and cholesterol uptake did not differ between the groups. Confocal imaging also revealed similar patterns of expression for the steroidogenic enzymes and their co-localization with mitochondria. Lastly, the expression of the other important genes regulating cumulus expansion, ovulation, and luteal function [Relaxin, ADAMTS-1, and epidermal growth factor (EGF)-like growth factor amphiregulin] in the GCs of the PPOS and antagonist cycles were similar.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Caution should be exercised when interpreting our data which was derived from normally responding patients whose ovulation was triggered with hCG. It is unclear whether the molecular parameters assessed vary according to infertility etiologies, magnitude of ovarian response, mode of trigger, and any other underlying ovarian pathologies or systemic diseases. MPA was the progestin used for PPOS and whether these findings can be generalized to other progestins is unknown.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides reassuring molecular evidence that exposure of antral follicle cohorts to MPA during the follicular growth phase does not have any detrimental effects on steroidogenic, ovulatory, and luteal functions when compared with GnRH antagonist cycles.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the School of Medicine, the Graduate School of Health Sciences of Koc University and Koç University Research Center for Translational Medicine (KUTTAM), and equally funded by the Republic of Turkey Ministry of Development Research Infrastructure Support Program. All authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Comparison of fixed and flexible progestin-primed ovarian stimulation in women classified in patient-oriented strategies encompassing individualized oocyte number (POSEIDON) group 4

PURPOSE

This study aimed to compare the fixed and flexible protocols for progestin-primed ovarian stimulation (PPOS) in poor ovarian responders.

METHODS

This retrospective study included 95 poor ovarian responders classified using the Patient-Oriented Strategies Encompassing Individualized Oocyte Number group 4 criteria. Treatment involved assisted reproductive medicine using fixed and flexible PPOS protocols at Shiga University of Medical Science between July 2019 and August 2023. PPOS cycles were assigned to the fixed and flexible groups at the discretion of attending physicians. The results of assisted reproductive medicine were compared between groups.

RESULTS

The fixed and flexible groups included 68 and 27 patients, respectively. The flexible group obtained more retrieved oocytes and two pro-nuclei than the fixed group, without an early luteinizing hormone surge. Multiple linear regression analysis demonstrated that differences in protocols and anti-müllerian hormone (AMH) levels were related to the number of retrieved oocytes. The differences in protocols were more strongly correlated with the number of oocytes than with the AMH levels.

CONCLUSION

Among poor ovarian responders, the flexible PPOS protocol provided more retrieved oocytes than the fixed PPOS protocol, possibly because the total dosage of progestins was lower in the flexible group and progestins were not administered at the time when ovarian stimulation was initiated.

Programming the onset of ovarian stimulation: from early follicular phase start to oral contraceptive pill, to luteal phase E2, Duostim, and random start oral contraceptive protocols

Ovarian stimulation has been the single most efficient measure ever taken in assisted reproductive technology for improving outcomes by harvesting multiple oocytes and ultimately, embryos. Today, ovarian stimulation protocols consist of administrating exogenous gonadotropins to override the natural mechanisms that control the ovulatory quota to one in humans. For practicality issues, there have been numerous attempts to control, or "program," when ovarian stimulation is initiated to improve functionality and in turn efficacy for assisted reproductive technology programs. The different options for controlling the onset of ovarian stimulation currently available are discussed here, as well as the novel possibility of using progestins for blocking premature ovulation.

Progestin-primed ovarian stimulation

PURPOSE OF REVIEW

The use of progestins as pituitary suppressors has increased progressively, along with more detailed indications for their use, thereby consolidating an alternative approach to the personalization of ovarian stimulation.

RECENT FINDINGS

Based on the ability of progesterone to inhibit ovulation, progestins have been used in ovarian stimulation (OS) follicular protocols to prevent a luteinizing hormone surge in patients undergoing in vitro fertilization (IVF), as an alternative to gonadotropin-releasing hormone (GnRH) analogue administration. This review explores the different types of progestogen protocols and their efficacy depending on the type of population or reproductive procedure in which they are administered and in comparison with that of GnRH analogues. Their effect on oocytes and embryos and their safety and cost-effectiveness are also analyzed.

SUMMARY

Progestins have proven their effectiveness as a gonadotropin adjuvant in terms of ovarian response, reproductive outcome, and safety. In addition, they offer the convenience of oral administration and a lower cost than GnRH analogues. Whereas oocytes or embryos should be vitrified as it displaces the receptive period with the consequent asynchrony between embryo and endometrium. The evidence endorses progestins as a more friendly approach to OS, especially when frozen-thawed embryo transfer is planned.

Verification of the utility of the gonadotropin starting dose calculator in progestin-primed ovarian stimulation: A comparison of empirical and calculated controlled ovarian stimulation

Purpose

To validate the effectiveness of a gonadotropin starting dose calculator for progestin-primed ovarian stimulation (PPOS), we conducted a study comparing the outcomes of oocyte retrieval between a group assigned gonadotropin doses via the calculator and a control group, where doses were determined by the clinician's empirical judgment.

Methods

Patients underwent controlled ovarian stimulation (COS) using the PPOS method, followed by oocyte retrieval. We assessed and compared the results of COS and oocyte retrieval in both groups. Additionally, we examined the concordance rate between the number of oocytes actually retrieved and the target number of oocytes in each group.

Results

The calculated group demonstrated a significantly higher number of preovulation follicles and a higher ovarian sensitivity index than the control group. Furthermore, the discrepancy between the target and actual number of oocytes retrieved was notably smaller in the calculated group. The concordance rate between the target and actual number of oocytes was significantly greater in the calculated group.

Conclusions

The gonadotropin starting dose calculator proved to be effective within the PPOS protocol, offering a reliable method for predicting the approximate number of oocytes to be retrieved, irrespective of the COS protocol employed.