P-617 Combined oral contraceptive pill (COCP) pre-treatment and progestin-primed ovarian stimulation (PPOS) protocol: a detrimental combination for the oocyte yield in egg donation programs

Abstract

Abstract Study question Could the use of combined oral contraceptive pill (COCP) pre-treatment before controlled ovarian hyperstimulation (COH) have a negative effect on oocyte yield in normo-responders patients? Summary answer When COH with progestin-primed ovarian stimulation (PPOS) protocol in normo-responders patients is performed, the COCP pre-treatment could have a detrimental effect on oocyte yield. What is known already COCP pre-treatment is widely used to schedule the start of COH and to organize the working week, but its usefulness and efficiency are still not clear. Most of studies on IVF outcomes have shown no effect of COCP on oocyte yield. For oocyte donation only few studies were carried out showing controversial effects on oocyte yield, but all considered short antagonist or long agonist protocols and no one PPOS protocol. COCP leads to long lasting pituitary suppression and lower LH level in follicular phase that could reduce the ability to effectively respond to GnRH-agonist trigger leading to poor oocyte yield. Study design, size, duration The egg donation cycles carried out from January to September 2022 in Next Fertility Valencia were retrospectively analyzed. Two analyses were conducted. Analysis A, comparative retrospective cohort study of 397 COH cycles: 290 with COCP and 107 without COCP. Analysis B, comparative retrospective paired study of 90 COH cycles: 45 with COCP and 45 without COCP, in which, to attempt to eliminate possible bias due to interpersonal differences, every patient was her own control. Participants/materials, setting, methods All donors underwent to COH with FSH monotherapy, PPOS protocol for pituitary suppression and a GnRH-agonist triggering. The oocyte yield was analyzed focusing on: the number of oocytes retrieved, mature (MII) oocytes and useful oocytes (good mature oocytes used for ICSI), the appropriate response to the GnRH-agonist trigger, the stimulation days, the total gonadotropins dose used and the cancellation rate (for low response or low LH level in follicular phase the first day of COH). Main results and the role of chance In both analyses, the data showed no differences in terms of stimulation days, total FSH dose, number of follicles ≥ 15 mm on the trigger day regardless of use of COCP. After conducting the analysis based on the administration or not of COCP, in the Analysis A a higher number of total oocytes retrieved, mature oocytes and useful oocytes were found in the group that did not used COCP. A significant difference in a nominal variable (Pearson's chi-square test) was observed, consisting of a higher proportion of cancellations due to low LH level (< 2,5 mUI/ml) in the group that used COCP (COCP no: 0.7% vs. COCP yes: 3.7% ). While, in the Analysis B (analysis of variance of one factor, Anova test), the variables total oocytes retrieved, total MII oocytes and total useful oocytes showed significant differences consisting of a higher number of oocytes in the group that did not received COCP. These results have statistical significance both before removing the cases in which the values were 0 due to a cancellation (p < 0.01), and after removing the cancelled cases (p < 0.05). Limitations, reasons for caution The main limitation lies in the retrospective nature of the study. However, since each patient is her own control (Paired study), it gives an added value. Wider implications of the findings COCP before COH in PPOS cycles could have detrimental effects on oocyte yield, reducing the efficacy and efficiency of egg donation programs. This could be extended to social freezing programs in normo-responders patients, in which the probability of future pregnancy is closely linked to the number of good oocytes vitrified. Trial registration number Not Applicable