Purpose: To determine if the injection of a gonadotropin releasing hormone agonist (GnRHa) three days after embryo transfer will improve pregnancy and implantation rates.
Materials and methods: One mg s.c. of leuprolide acetate was randomly given based on patient decision three days after embryo transfer to some patients undergoing in vitro fertilization-embryo transfer (IVF-ET).
Results: For women aged ≤ 43 the clinical pregnancy rate for those not taking the GnRHa was 39.5% (68/122) vs. 54.5% (42/77) for those taking leuprolide acetate (Chi-square, p = 0.0275). The respective implantation rates were 22.6% vs. 30.2% (p = 0.0495). There was no difference in first serum beta human chorionic gonadotropin (beta-hCG) levels according to whether leuprolide was used or not.
Conclusions: Leuprolide acetate similar to other GnRH agonists can improve implantation rates following IVF-ET when injected once in mid-luteal phase. The beneficial effect may be on GnRH receptors in the endometrium rather than the embryo (which had been hypothesized to direct increased placental production of hCG).