Controlled ovarian hyperstimulation in women > or = 40 years old undergoing IVF-ET: mid-luteal versus early follicular (flare-up) GnRH analog regimens.

The aim of this study was to compare results obtained using two different GnRH analogue regimens in women > or = 40 undergoing IVF cycles. Patients using GnRH-a from mid-luteal phase of the previous cycle (group A) needed more days of ovarian stimulation than patients GnRH-a in the follicular phase of the same cycle "flare-up" (group B) (11.7 +/- 1.3 vs 10.8 +/- 2 respectively). Group A patients developed more follicles and obtained more oocytes than group B (9.2 +/- 4.9 vs 6.1 +/- 4.4; And 7.6 +/- 4.7 vs 4.2 +/- 3.2, respectively). The cancellation rate was significantly higher in B than A (20 vs 8.6%, respectively). Pregnancy rates however were significantly lower in "flare-up" than in mid-luteal group (3 vs 14% per cycle, 4.7 vs 17% per patient, 3.8 vs 15.2% per oocyte retrieval and 5.4 vs 18.8% per transfer, respectively). Different results obtained in the two groups suggest that Gn-RH-a long protocol allows better ovarian stimulation and consequently improved pregnancy rate than "flare-up" in women > or = 40 years old.