Cumulative live birth rates do not increase after 4 complete cycles in women with poor ovarian response: a retrospective study of 1,825 patients

Objective: To investigate whether the cumulative clinical pregnancy rates (CCPR) and cumulative live birth rates (CLBR) increase as the oocyte retrieval cycle increases in women with poor ovarian response. Design: Retrospective cohort study. Setting: Not applicable. Patient(s): Women diagnosed of poor ovarian response (POR) according to the Bologna criteria and who completed in vitro fertilization or intracytoplasmic sperm injection cycles between January 2014 and December 2018. Intervention(s): Not applicable. Main Outcome Measure(s): The conservative and optimistic estimations of CCPR and CLBR. Result(s): The conservative and optimistic estimates of CCPR peaked at the 6th complete cycle, reaching 36.44% and 71.61%, respectively. However, the conservative and optimistic estimates of CLBR peaked at the 4th complete cycle, reaching 20.22% and 38.31%, respectively. The live birth rate per complete cycle of mild stimulation protocol was comparable to other protocols after adjusting for the confounding factors. For patients ≤35 years, the live birth rate per complete cycle of progestin-primed ovarian stimulation (adjusted odds ratio = 0.51, 95% confidence interval: 0.30–0.87) and gonadotropin-releasing hormone antagonist protocol (adjusted odds ratio=0.45, 95% confidence interval: 0.24–0.81) were significantly lower than that of the mild stimulation. Conclusion(s): It is not advisable to initiate more than four complete cycles for POR patients since CLBR do not increase after that. For POR patients ≤35 years, the live birth rate per complete cycle increased in women with mild stimulation protocol.