Follicular fluid inhibin levels in relation to age in patients in an in vitro fertilization and embryo transfer programme.

Inhibin (INH), oestradiol (E2) and progesterone (P) were measured in the follicular fluid (FF) of 22 patients 28-38 years old (Group A) and 11 patients 43-47 years old (Group B) who had received gonadotrophin stimulation in an in vitro fertilization and embryo transfer (IVF-ET) programme. The results indicated that INH, E2 and P levels were significantly lower and the E2/P ratio was higher in FF of Group B patients (older women) compared to those of Group A. There were six single pregnancies among patients of Group A. No difference was observed in follicular fluid INH, E2 and P levels as well as in E2/P ratio between pregnant and non-pregnant patients of Group A (Group A1 and Group A2, respectively). A positive correlation was found between FF concentrations of E2 and P, E2 and INH and P and INH in the three Groups and a negative one between INH and the E2/P ratio in Group B. It seems likely that ovarian INH and E2 production are controlled by different mechanisms and that INH response to ovarian hyperstimulation is altered by advancing age.