High FSH:LH ratio and low LH levels in basal cycle day 3: impact on follicular development and IVF outcome

To examine the impact of low basal cycle day 3 serum LH levels or a high FSH:LH ratio on IVF results.

A homogeneous group of patients was analyzed as identified by normal basal cycle of follicle stimulating hormone (FSH), Luteinizing hormone (LH), and estradiol (E2) levels. High responders (high LH:FSH ratio) and low responders (high FSH or E2 levels, and women > or = 42 years of age) were excluded from analysis. Only cycles stimulated with a combination of a GnRHa (luteal suppression) and pure FSH were studied.

Patients with low basal LH levels (< 3 mIU/mL) did not differ significantly from controls in terms of response to controlled ovarian hyperstimulation but there was a clear trend toward poorer implantation and clinical pregnancy rates. On the other hand, patients with a high FSH:LH ratio (> 3) had significantly fewer mature oocytes aspirated, and lower implantation and clinical pregnancy rates than patients with gonadotropin ratio < or = 3. These negative effects were evident in the presence of normal basal FSH levels and after adequate matching of female's age and number of embryos transferred.

These studies highlight a negative impact of a basal cycle high FSH:LH ratio (and possibly low LH levels) on follicular development and oocyte quality in these patients subjected to pituitary down-regulation followed by pure FSH administration. A high FSH:LH ratio may be therefore used as an early biomarker of poor ovarian response.