Triggering Ovulation with Gonadotropin-releasing Hormone Agonists Does Not Compromise Embryo Implantation Rates

Objective: To evaluate the implant capacity of embryos derived from oocytes matured with a bolus of GnRH agonist.

Design: Donors were randomly assigned to a protocol using either GnRH agonist or recombinant (r) hCG to trigger ovulation. Analysis of variance, Student t test, and Fisher exact test were used where appropriate.

Setting: Private clinical setting.

Patient(s): Young voluntary donors receiving GnRH agonist (n = 30) or rhCG (n = 30). Eighty-nine patients received oocytes.

Intervention(s): Controlled ovarian stimulation was carried out with GnRH antagonist and FSH/LH in a step-down protocol. Donors received a single bolus of GnRH agonist (0.2 mg) or rhCG (250 microg). The endometrial tissue of recipient patients was prepared with oral E(2) and P.

Main Outcome Measure(s): Pregnancy and implantation rates and ovarian hyperstimulation syndrome (OHSS) in an IVF donor program.

Result(s): No significant differences in the number of retrieved oocytes (327 vs. 288), MII oocytes (70% vs. 76%), fertilization (80% vs. 65%,), pregnancy/transfer (55% vs. 59%), and implantation rates (29% vs. 32%) were found between recipients whose embryos originated from donors in whom final oocyte maturation was triggered with GnRH agonist and those whose donors received hCG. Significant differences in luteal phase length (4.16 + 0.70 days vs. 13.63 + 2.12 days) and in OHSS (0/30 vs. 5/30) were seen between donors ovulated with the agonist and the donors in whom ovulation was triggered with hCG.

Conclusion(s): In controlled ovarian stimulation IVF donor cycles, GnRH agonists trigger ovulation and induce luteolysis but do not compromise embryo implantation capacity.