Effects of ovarian response prediction index and follicle-oocyte index on pregnancy outcomes: a retrospective cohort study of 12,218 fresh transfer cycles

Abstract

Objective: To investigate the potential relationships among the ovarian response prediction index (ORPI), follicle-oocyte index (FOI), and clinical pregnancy rate (CPR) in women undergoing their first in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) fresh cycle transfer. Methods: In this retrospective cohort study, we included 12,218 women who underwent their first IVF/ICSI-ET cycle between December 2014 and January 2021. The primary and secondary outcomes of our study were CPR and cumulative live birth rate (CLBR), respectively. The data were divided into three groups according to the ORPI and FOI tertiles. Multivariate logistic regression analyses, stratification analyses, interaction, restricted cubic splines, and receiver operating characteristic (ROC) curves were constructed to identify the relationships among ORPI, FOI, and CPR. Results: A statistically significant increase in CPR was detected from the lowest to the highest tertile group (ORPI: 48.12%, 54.07%, and 53.47%, P <0.001; FOI: 49.99%, 52.95%, and 52.71%, P = 0.012). A higher CLBR was observed in the high group (ORPI: 38.63%, 44.62%, and 44.19%, P <0.001; FOI: 41.02%, 43.78%, and 42.59%, P = 0.039). Multivariate logistic regression analysis revealed no statistically significant differences between ORPI, FOI, and neither CPR (odds ratio [OR] [95% confidence interval {CI}], 0.99 [0.97–1.00] vs. [1.02 {0.84–1.24}]) nor CLBR (OR [95% CI], 0.99 [0.97–1.01] vs. 0.99 [0.81–1.20]). No significant association was found among FOI, ORPI, and CPR, even in the subgroups. Restricted cubic spline analyses indicated the existence of a non-linear relationship across the entire range of FOI and ORPI. The ORPI and FOI variables had poor predictive ability (AUC < 0.60) for CPR. Conclusions: Both ORPI and FOI are not reliable predictors of clinical pregnancy or live birth outcomes in fresh ETs. Clinicians and researchers should avoid using FOI and ORPI to assess pregnancy outcomes after fresh ET because of their limited relevance and predictive value.