Optimum Number of Oocytes Retrieved Among Patients With Polycystic Ovary Syndrome Treated Using The Follicular Phase Long-Acting Long Protocol: A Retrospective Cohort Study

Abstract

Background: The optimum number of oocytes retrieved by the follicular phase long-acting long protocol is still unknown. This study aimed to analyze the optimum oocyte number in patients with polycystic ovary syndrome (PCOS) undergoing this protocol.Methods: A total of 1816 PCOS patients aged <35 years who were undergoing their first cycle of in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) between January 2017 and June 2019 were identified and reviewed. All patients underwent stimulation using a follicular phase long-acting long protocol. In this retrospective cohort study, patients were categorized into seven groups according to the number of oocytes retrieved (group A, 1–5; group B, 6–10; group C, 11–15; group D, 16–20; group E, 21–25; group F, 26–30; group G, >30). The main outcome indicators were the rates of high-quality embryo, fresh cycle pregnancy, cumulative pregnancy, and “freezing all” for high ovarian response. The cumulative pregnancy and “freezing all” rates for high ovarian response were analyzed using multivariate logistic analysis.Results: The high-quality embryo rate decreased with the increase in the number of oocytes retrieved (P<0.001). In the <20 oocyte group, the clinical and cumulative pregnancy rates increased with the number of oocytes retrieved, and the “freezing all” rate for high response was within 30%. In the >20 oocyte group, with an increase in the number of oocytes retrieved, no significant change was found in the clinical and cumulative pregnancy rates (P>0.05); however, the incidence of “freezing all” rate for high response was significantly increased (P<0.001). After correcting for confounding factors, the number of oocytes retrieved was an independent predictor of the “freezing all” rate for high ovarian response (odds ratio [OR], 1.085; 95% confidence interval [CI] 1.057–1.113) and cumulative pregnancy rate (OR 1.091, 95% CI 1.057–1.126). The high-quality embryo rate was significantly affected by the cumulative pregnancy rate (OR, 59.076; 95% CI: 29.591–117.938).Conclusion: In PCOS patients aged <35 years treated using the follicular phase long-acting long protocol, considering clinical outcomes, laboratory indicators, and safety, appropriate ovarian stimulation should be used to control the number of oocytes retrieved at 11–20.