PREDICTABILITY OF OVARIAN SENSITIVITY INDEX FOR ANTAGONIST-PROTOCOL ICSI CYCLE OUTCOMES.

This retrospective cohort study aims to revisit the generalizability and determine the predictability of the ovarian sensitivity index (OSI) for ICSI cycle outcomes. Women for ICSI in tertiary ART unit from January 2016 through 2020 were screened. Women were eligible if they had oocyte retrieval in fresh antagonist FSH/hMG stimulated cycles. OSI is calculated as oocytes retrieved × 1000/total gonadotropin dose. OSI standards determined by Huber et al. (1) were utilized to categorize women with OSI <1.69, 1.69-10.07, and >10.07 to poor-, normal-, and high-responders, respectively. For discriminative analysis, predictive and validation analytic models were constructed from total sample (n=622) by randomization in a 1:2 ratio, respectively. The OSI cutoffs, based on ROC analysis with Youden index that predicted clinical pregnancy (CP) and live birth (LB) in the predictive model, were further validated in the validation cohort. Multivariate bootstrapped logistic regression was done for the predictability of OSI for cycle outcomes, adjusted for other covariates. 622 cycles were eligible for analysis. Women had a median (IQR) age of 30 (6) years, BMI of 28 (5.5) kg/m2, and AMH of 2.1(2.3) ng/ml. CP and LB rates per retrieval were 36.2% and 27.7%, respectively. Based on Huber’s OSI, the cohort included poor (18.8%), normal (71.2 %) and high (10%) responders with a mean OSI of 1.04±0.41, 4.89±2.25, and 13.05±2.90, P< .001, respectively. High-responders had a higher CP (58.1% vs 36.4% vs 23.2%, P< .001), LB (50% vs 28% vs 14.5%, P