Ovarian response to standard gonadotrophin stimulation for IVF is decreased not only in older but also in younger women in couples with idiopathic and male subfertility.

BACKGROUND With the occasional reports of unexpectedly poor ovarian response to controlled ovarian hyperstimulation (COH) for IVF in young normally cyclic women in mind, we studied age-related ovarian response to COH in a group of women who underwent standard IVF. METHODS Ovarian response to COH was defined as the number of follicles > or = 14 mm on the day of hCG administration. Ovarian response to COH was analysed by multiple regression analysis with woman's age and basal FSH concentration as explanatory variables in a prospective cohort of patients with idiopathic and mild male factor subfertility (n = 85), and additionally in a large retrospective cohort of women with unexplained, mild male and tubal subfertility (n = 1155), with age as explanatory variable. RESULTS Ovarian response to COH was associated significantly with age (P < 0.001) and basal FSH concentration (P = 0.002). However, in women with idiopathic or mild male subfertility, in both cohorts the relationship took the form of an inverted U-shape with both older and--surprisingly--young women having a reduced ovarian response (P < 0.001). Maximum ovarian response was around the age of 28 years. In women with tubal infertility, there was only a linear decline of ovarian response with age. CONCLUSION It is hypothesized that diminished ovarian response to COH in IVF is the very first sign of ovarian ageing in young women diagnosed with idiopathic and mild male subfertility.