Triggering with GnRH agonist in oocyte-donation cycles: oestradiol monitoring is not necessary during ovarian stimulation

This prospective observational study evaluated the efficacy and safety of oocyte-donation cycles triggered with a gonadotrophin-releasing hormone (GnRH) agonist without monitoring oestradiol concentrations during ovarian stimulation. A total of 97 oocyte donors received recombinant FSH (150-225/day) and GnRH antagonists (0.25 mg/day). Oocyte maturation was triggered with 0.2 mg triptorelin s.c. Donors aged 25.4 +/- 4.1 years were stimulated for 8.8 +/- 0.9 days and underwent 2.9 +/- 0.5 (2-4) ultrasound assessments. Total FSH dose was 1703.4 +/- 304.7 IU, antagonists were administered for 4.3 +/- 1.0 days, 14.7 +/- 8.8 oocytes were retrieved and there were no cases of ovarian hyperstimulation syndrome. Recipients (n = 123) aged 40.3 +/- 3.4 years received 10.9 +/- 4.3 oocytes, 88.7% of which were metaphase II. Intracytoplasmic sperm injection fertilization rate was 79% and 2.18 +/- 0.6 (1-3) embryos were transferred. The pregnancy, clinical pregnancy and twin pregnancy rates were 64.2%, 57.7% and 19.7%, respectively. In conclusion, given the high efficacy and safety of the GnRH-antagonist protocol triggered with a GnRH agonist, the monitoring of oestradiol concentrations is not necessary. Ultrasound monitoring is enough for an adequate follow up of the stimulation cycle in oocyte donors. (C) 2011, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.