Objectives: Assessment of the applicability of estimated serum inhibin A (INHA) and/or INHB versus estradiol (E2) levels to determine the triggering time during controlled ovarian stimulation (COS) that might allow the retrieval of the optimal number of oocytes.

Patients: 196 infertile women assigned to receive COS

using the flexible antagonist protocol gave blood samples for ELISA estimation of serum levels of E2 and INHs on day-2 of the cycle and on the day of retrieval depending on having serum E2 levels >2000 pg/ml and the optimal number of follicles; 11-15 follicles of≥16 mm in diameter. The study outcome is the blinded distinguishing ability of estimated serum levels of E2 and INHs between cases that might have 2000

pg/ml) showed sensitivity and specificity rates of 89.8% and 40.6% to distinguish women who had