Objective: To determine the predictive value of the inhibin B increment during controlled ovarian hyperstimulation (COH) for differentiating between poor and normal responders and for deciding whether to continue or stop an IVF attempt.
Design: Prospective study.
Setting: Assisted reproduction unit at a university hospital.
Patient(s): A total of 110 women undergoing IVF for idiopathic, tubal, and/or male infertility.
Intervention(s): Blood samples were collected on days 6 and 8 of COH. Inhibin B and E(2) assays were performed.
Main outcomes measure(s): The degree of inhibin B increment was defined as Delta IB = day-8 value minus day-6 value. We analyzed the correlation of day-6 and day-8 inhibin B values and Delta IB with the number of oocytes retrieved. The predictive value of each parameter was determined by using the receiving operator characteristics curve analysis.
Result(s): The Delta IB correlated best with the number of oocytes retrieved (r = 0.5) and with the number of embryos obtained (r = 0.26), independently of age. From the receiving operator characteristics curve analysis, a Delta IB cutoff value of 300 pg/mL discriminated poor (few than four oocytes retrieved, n = 16) from normal (more than four oocytes retrieved, n = 94) responders, with a sensitivity of 70% and a specificity of 94%.
Conclusion(s): The degree of inhibin B increment during COH provides additional information for predicting ovarian response to COH. An increment >300 pg/mL is required to rule out the eventuality of a poor ovarian response.