Comparison of GnRH agonists and antagonists in normoresponder IVF/ICSI in Turkish female patients.

Purpose: To evaluate the results of gonadotropin-releasing hormone agonist (GnRHa) and gonadotropin-releasing hormone antagonist (GnRHant) use in two demographically matched groups of normoresponder in-vitro fertilisation or intracytoplasmic sperm injection (IVF/ICSI) patients in a prospective study.

Methods: We randomised 93 patients undergoing IVF/ICSI between May 2005 and August 2006. Patients with IVF indications were included except for those with polycystic ovary syndrome or azoospermia, women older than 38 years and those with follicle-stimulating hormone (FSH) > or =10 IU/ml. Patients were stimulated with standard 225 IU recombinant FSH. In Group I (n=45) a daily dose of GnRHant cetrorelix acetate 0.25 mg was administered when follicles reached a diameter of > or =14 mm. Group II (n=48) patients were desensitised with the GnRHa, leuprolide acetate, in a long protocol. Human chorionic gonadotropin (hCG) was administered when at least three follicles of 18 mm in diameter were observed. Oocyte retrieval was scheduled 36 hours following hCG administration and embryos were transferred on day 3 after oocyte retrieval.

Results: The two groups were homogenous for age, infertility duration, basal FSH and serum oestradiol (E2) (P=0.537, P=0.911, P=0.103 and P=0.733, respectively). In Group II (the GnRHa group) more antral follicles (P<0.001), a longer induction duration (P=0.017) and higher peak E2 levels (P<0.001) were observed. No differences were observed in the number of oocytes retrieved (P=0.749), embryos achieved and transferred (P=0.677), or fertilisation rates (P=0.839) between the two groups. There was no statistically significant difference between groups in clinical pregnancy rates, cycle cancellation and ovarian hyperstimulation (P=0.437, P=0.109 and P=0.415, respectively).

Conclusion: GnRHant and GnRHa provide comparable results in normoresponder patients, while GnRHant allows a greater flexibility in their treatment.