High basal LH levels in combination with low basal FSH levels are associated with high success rates at assisted reproduction

BACKGROUND: The objective of this study was to evaluate the associations of basal gonadotrophins with pregnancy and delivery rates at IVF/ICSI. METHODS: A prospective observational study was conducted at a university-affiliated private infertility centre. Patients were 745 women, who underwent 1328 IVF/ICSI treatment cycles. Basal FSH, basal LH and combinations of FSH and LH versus treatment data and pregnancy and delivery rates were measured. RESULTS: Combinations of FSH and LH gave significantly better information than the LH:FSH ratio, or each gonadotrophin alone: highest mean pregnancy rate (39%) was achieved in women with low FSH (<6.7 U/l) and with high LH levels (>4.9 U/l), whereas pregnancy rate was lowest (22%) in women with high FSH and low LH levels. Pregnancy rates were intermediate (27-28%) if FSH and LH were either both low or both high (P for trend = 0.0004). Associations to delivery rates and measures of ovarian response and embryo quality followed the same pattern. CONCLUSIONS: Basal LH modifies and improves the information given by basal FSH alone. Low FSH level combined with high LH probably reflects a well-preserved ovarian reserve and is associated with the highest success rates at IVF/ICSI.