Elevated day 3 FSH/LH ratio due to low LH concentrations predicts reduced ovarian response

Adequate ovarian response, essential for successful IVF, cannot be accurately predicted. This study retrospectively reviewed all patients undergoing IVF from 1998 to 2001. Inclusion criteria were age <41 years at treatment onset and a basal day 3 serum FSH concentration <12 IU/l. Women with FSH ≤8 IU/l underwent a secondary analysis. Two groups emerged according to basal day 3 serum FSH/LH ratio: ≥3 in group 1 and <3 in group 2 (controls). Age at treatment initiation, basal serum day 3 FSH and LH concentrations, peak serum oestradiol concentration, number of retrieved and fertilized oocytes and pregnancy rate were analysed. Groups 1 (n = 41, 111 IVF treatment cycles) and 2 (n = 596, 1434 IVF treatment cycles) were similar in term of woman's mean age. Group 1 had significantly higher mean basal day 3 FSH concentration (P < 0.01) and significantly lower oestradiol concentrations at oocyte retrieval (P < 0.01), mean number of oocytes retrieved and fertilized (P < 0.01) and pregnancy rate (P = 0.016). The same trend persisted after excluding 98 patients with basal FSH concentrations >8 IU/l. In conclusion, elevated day 3 FSH/LH ratio is associated with an inferior outcome in IVF treatment cycles and may be used as an additional predictor for decreased ovarian response.