Clinical impact of premature luteinizing hormone (LH) rises prior to the start of ganirelix treatment on day 5 or day 6 of stimulation

To evaluate the incidence, and potential clinical impact, of premature LH rises prior to the start of daily ganirelix (0.25 mg) treatment on day 5 or 6 of controlled ovarian stimulation (COS). Retrospective pooled analysis of 3 trials with a fixed ganirelix treatment start on day 5 (n = 961) and 6 trials with a fixed ganirelix treatment start on day 6 (n = 1205) of COS with 150-225 IU recombinant follicle-stimulating hormone (rFSH). Serum LH concentrations were centrally measured using the same validated immunoassay (Delfia) and an LH rise was defined as LH ≥10.0 IU/L as compared to baseline. Patient characteristics were similar between trials with ganirelix starting on day 5 or 6. In trials with ganirelix treatment starting on day 5, the incidence of early LH rises prior to the start of ganirelix was 2.3% (95% CI, 1.4–3.4). In these trials, patients with an early LH rise had a higher mean [SD] number of oocytes per started cycle as compared to patients without early LH rise (16.0 [8.9] vs 11.8 [6.6]), whereas the ongoing pregnancy rates per started cycle were very similar (36.4% and 35.8%). In trials with ganirelix treatment starting on day 6, incidence of early LH rise prior to the start of ganirelix was 6.3% (95% CI, 4.9–7.8). Per started cycle, the number of oocytes retrieved in patients with vs without an early LH rise was 11.9 (8.2) vs 8.8 (5.8), respectively, and the ongoing pregnancy rate was 22.7% in both groups. This combined analysis indicates that early LH rises may occur more frequently in patients with a relatively high ovarian response and that the incidence can be reduced by initiating ganirelix on stimulation day 5 rather than on day 6. The clinical impact of these early LH rises seems limited as the ongoing pregnancy rates were not compromised. These results support a flexible regimen of starting ganirelix treatment on day 5 or day 6 of COS, depending on the ovarian response.