Changes of Serum Inhibin Concentration in Controlled Ovarian Hyperstimulation for IVF-ET

Moon, Shin Yong; Kim, Seok Hyun; Lee, Jae Hoon; Suh, Chang Suk

Abstract

Inhibin is a glycoprotein usually produced by granulosa cell of ovary and is known as regulator of FSH secretion. Inhibin is consisted of two heterodimeric subunit of a, B . There are two distinct molecular forms of the B subunit that exist (BA and BB) and when combined with an a subunit, form inhibin A, and inhibin B, respectively. Ovarian reserve describes women's reproductive potential, which usually decreased according to chronological age. Because useful markers claimed for the prediction of ovarian response during controlled ovarian hyperstimulation for IVF-ET have not been always successful, new biomarker has been investigated. The purpose of this study was to observe the changes in serum and ovarian follicular inhibin A concentration during controlled ovarian hyperstimulation for IVF-ET program and to evaluate the clinical significance of inhibin A as a prognostic marker for assisted reproductive technology outcomes. From Jan 1996 to Dec 1996, 48 patients who underwent IVF-ET were included. In each patient, the Day 3 FSH, LH, E2q were measured in the first month of cycle before commencing GnRH agonist administration, In the stimulation period after pituitary down regulation, blood samples for inhibin A were collected at the day 3, day 7, day of hCG injection, day of oocytes aspiration, and day of embryo transfer. Ovarian follicular inhibin A was collected at the day of oocyte aspiration. Inhibin A concentration was measured using test kit for inhibin A (INHIBIN-EASIA (code 40.134.00), Belgium Medgenix). The changes in serum inhibin A, E2 concentration during IVF-ET program showed increasing pattern throughout controlled ovarian hyperstimulation periods. If the cut-off value of day 3 serum inhibin A determined to 0.28 U/ml, the sensitivity and specificity were 80.0%, 75.0% respectively in predicting the number of oocytes retrieved being more than five. If the cut-off value of peak serum E determined to 1316 pg/ml, the sensitivity and specificity were 89.0%, 100.0% respectively in predicting the number of oocytes retrieved being more than five. In conclusion, measurement of serum inhibin A concentration on the day of starting stimulation (day 3) could be used as a useful marker for predicting the ovarian response in IVF-ET program.