Androgen and inhibin B levels during ovarian stimulation before and after 8 weeks of low-dose hCG priming in women with low ovarian reserve.

STUDY QUESTION: Does 8 weeks of daily low-dose hCG administration affect androgen or inhibin B levels in serum and/or follicular fluid (FF) during the subsequent IVF/ICSI cycle in women with low ovarian reserve? SUMMARY ANSWER: Androgen levels in serum and FF, and inhibin B levels in serum, decreased following 8 weeks of hCG administration. WHAT IS KNOWN ALREADY: Recently, we showed that 8 weeks of low-dose hCG priming, in between two IVF/ICSI treatments in women with poor ovarian responder (anti-Müllerian hormone (AMH) <6.29 pmol/l), resulted in more follicles of 2-5 mm and less of 6-10-mm diameter at the start of stimulation and more retrieved oocytes at oocyte retrieval. The duration of stimulation and total FSH consumption was increased in the IVF/ICSI cycle after priming. Hypothetically, hCG priming stimulates intraovarian androgen synthesis causing upregulation of FSH receptors (FSHR) on granulosa cells. It was therefore unexpected that antral follicles were smaller and the stimulation time longer after hCG priming. This might indicate a different mechanism of action than previously suggested. STUDY DESIGN, SIZE, DURATION: Blood samples were drawn on stimulation day 1, stimulation days 5-6, trigger day, day of oocyte retrieval, and oocyte retrieval + 5 days in the IVF/ICSI cycles before and after hCG priming (the control and study cycles, respectively). FF was collected from the first aspirated follicle on both sides during oocyte retrieval in both cycles. The study was conducted as a prospective, paired, non-blinded, single-center study conducted between January 2021 and July 2021 at a tertiary care center. The 20 participants underwent two identical IVF/ICSI treatments: a control cycle including elective freezing of all blastocysts and a study cycle with fresh blastocyst transfer. The control and study cycles were separated by 8 weeks (two menstrual cycles) of hCG priming by daily injections of 260 IU recombinant hCG. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women aged 18-40 years with cycle lengths of 23-35 days and AMH <6.29 pmol/l were included. Control and study IVF/ICSI cycles were performed in a fixed GnRH-antagonist protocol. MAIN RESULTS AND THE ROLE OF CHANCE: Inhibin B was lower on stimulation day 1 after hCG priming (P = 0.05). Dehydroepiandrosterone sulfate (DHEAS) was significantly lower on stimulation day 1 (P = 0.03), and DHEAS and androstenedione were significantly lower on stimulation days 5-6 after priming (P = 0.02 and P = 0.02) The testosterone level in FF was significantly lower in the study cycle (P = 0.008), while the concentrations of inhibin B and androstenedione in the FF did not differ between the study and control cycles. A lower serum inhibin B in the study cycle corresponds with the antral follicles being significantly smaller after priming, and this probably led to a longer stimulation time in the study cycle. This contradicts the theory that hCG priming increases the intraovarian androgen level, which in turn causes more FSHR on developing (antral up to preovulatory) follicles. However, based on this study, we cannot rule out that an increased intra-follicular androgen level was present at initiation of the ovarian stimulation, without elevating the androgen level in serum and that an increased androgen level may have rescued some small antral follicles that would have otherwise undergone atresia by the end of the previous menstrual cycle. We retrieved significantly more oocytes in the Study cycle, and the production of estradiol per follicle ≥10-mm diameter on trigger day was comparable in the study and control cycles, suggesting that the rescued follicles were competent in terms of producing oocytes and steroid hormones. LIMITATIONS, REASONS FOR CAUTION: The sample size was small, and the study was not randomized. Our study design did not allow for the measurement and comparison of androgen levels or FSHR expression in small antral follicles before and immediately after the hCG-priming period. WIDER IMPLICATIONS OF THE FINDINGS: The results make us question the mechanism of action behind hCG priming prior to IVF. It is important to design a study with the puncture of small antral follicles before and immediately after priming to investigate the proposed hypothesis. Improved cycle outcomes, i.e. more retrieved oocytes, must be confirmed in a larger, preferably randomized study. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by an unrestricted grant from Gedeon Richter awarded to the institution. A.P. reports personal consulting fees from PregLem SA, Novo Nordisk A/S, Ferring Pharmaceuticals A/S, Gedeon Richter Nordics AB, Cryos International, and Merck A/S outside the submitted work and payment or honoraria for lectures from Gedeon Richter Nordics AB, Ferring Pharmaceuticals A/S, Merck A/S, and Theramex and Organon & Co and payment for participation in an advisory board for Preglem. Grants to the institution have been provided by Gedeon Richter Nordics AB, Ferring Pharmaceuticals A/S, and Merck A/S, and equipment and travel support has been given to the institution by Gedeon Richter Nordics AB. The remaining authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT04643925.

Eight weeks of androgen priming by daily low-dose hCG injections before ICSI treatment in women with low ovarian reserve.

STUDY QUESTION: Does 8 weeks of continuous low-dose hCG administration increase the proportion of antral follicles that reach the preovulatory state during ovarian stimulation (OS) in women with low ovarian reserve? SUMMARY ANSWER: The proportion of antral follicles (2-10 mm) that reached the preovulatory state did not increase. WHAT IS KNOWN ALREADY: The administration of androgens prior to OS might upregulate FSH receptor (FSHR) expression on granulosa cells, making follicles more responsive to exogenous FSH stimulation during OS. LH and hCG stimulate the local follicular androgen synthesis in theca cells and may be used as an endogenous androgen priming method. Exogenous priming by testosterone and dehydroepiandrosterone (DHEA) have been shown to increase the number of retrieved oocytes and live birth rate but the studies are small, and their use is associated with side effects. STUDY DESIGN, SIZE, DURATION: A prospective, paired, non-blinded single-center study including 20 women serving as their own controls conducted between January 2021 and July 2021 at The University Hospital Copenhagen Rigshospitalet, Denmark. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants underwent two identical consecutive IVF/ICSI treatments, a Control cycle and a Study cycle, separated by ∼8 weeks (two menstrual cycles) of daily injections of 260 IU recombinant hCG (rhCG). A freeze-all strategy was applied in the Control cycle. Both IVF/ICSI cycles were performed in a fixed GnRH antagonist protocol using a daily dose of 300 IU recombinant FSH (rFSH) and GnRH antagonist 0.25 mg from stimulation days 5-6. MAIN RESULTS AND THE ROLE OF CHANCE: Follicular output rate, defined as the number of follicles >16 mm on hCG trigger day divided by the antral follicle count (2-10 mm) at baseline, did not increase after 8 weeks of hCG priming (P = 0.8). The mean number of oocytes retrieved was significantly higher after the hCG priming being 4.7 (2.8) vs 3.2 (1.7) in the Study and Control cycle, respectively (P = 0.01). The duration of stimulation was longer in the Study versus the Control cycle (P = 0.05), despite the use of identical hCG trigger criterion and similar diameters of the three biggest follicles on hCG trigger day in the two cycles (P = 0.9). LIMITATIONS, REASONS FOR CAUTION: The sample size was small, and the number of oocytes retrieved was not the primary endpoint. Larger studies are needed to confirm this finding. WIDER IMPLICATIONS OF THE FINDINGS: Long-term, low-dose rhCG administration may increase the number of oocytes retrieved during IVF/ICSI in women with low ovarian reserve, but more research is needed before firm conclusions can be drawn. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by an unrestricted grant from Gedeon Richter. A.P. reports personal consulting fees from PregLem SA, Novo Nordisk A/S, Ferring Pharmaceuticals A/S, Gedeon Richter Nordics AB, Cryos International, and Merck A/S outside the submitted work and payment or honoraria for lectures from Gedeon Richter Nordics AB, Ferring Pharmaceuticals A/S, Merck A/S, and Theramex and Organon & Co. Grants to the institution have been provided by Gedeon Richter Nordics AB, Ferring Pharmaceuticals A/S, and Merck A/S and receipt of equipment by the institution from Gedeon Richter Nordics AB is reported. The remaining authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT04643925.

Response to ovulation trigger is correlated to late follicular phase progesterone levels: A hypothesis explaining reduced reproductive outcomes caused by increased late follicular progesterone rise.

STUDY QUESTION: Is there an association between progesterone (P4) levels on the day of hCG or GnRH trigger and on the day of oocyte retrieval in IVF/ICSI cycles? SUMMARY ANSWER: A significant positive correlation between P4 levels on the day of trigger and the day of oocyte retrieval is seen; HCG trigger induces a steeper P4 increase than GnRHa trigger. WHAT IS KNOWN ALREADY: FSH induces LH receptor (LHR) expression on granulosa cells, and LHR produces progesterone when exposed to LH-like activity. FSH per se also to some extent induces P4 secretion. Late follicular phase progesterone rise has been associated with reduced reproductive outcomes. STUDY DESIGN, SIZE, DURATION: This study is based on data from a previously published RCT conducted from 2009 to 2011. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 384 participants were enrolled; 199 received 5000 IU hCG and 185 received buserelin 0.5 mg for triggering ovulation. P4 was measured on the day of ovulation induction and on the day of oocyte retrieval. FSH consumption and number of retrieved follicles were recorded. MAIN RESULTS AND THE ROLE OF CHANCE: A significant linear relationship between P4 on the day of ovulation induction and oocyte retrieval was seen in the hCG trigger group (P < 0.00001) as well as in the GnRHa trigger group (P < 0.00001). The P4 ratio (the increase in P4 between ovulation induction and oocyte retrieval) was significantly higher in the group of patients with <5 follicles compared to those with 5-15 and >15 follicles (P < 0.0001). The FSH consumption per follicle was significantly higher in the group of patients with <5 follicles compared to those with 5-15 and >15 follicles (P < 0.0001). LIMITATIONS, REASONS FOR CAUTION: Although the study demonstrates a significant correlation between P4 levels before and after ovulation trigger, it does not demonstrate a causal relation to the number of LHRs present on granulosa cells. WIDER IMPLICATIONS OF THE FINDINGS: The findings of this study support the proposed hypothesis that follicles exposed to high levels of FSH during ovarian stimulation will respond with an inappropriately high LHR expression. This in turn causes a high P4 output in response to the trigger. This study further expands our understanding of the underlying mechanisms affecting reproductive outcomes in relation to ovarian stimulation. STUDY FUNDING/COMPETING INTEREST(S): The authors received no specific funding for this work and disclose no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.