Effect of duration of the GnRH agonists in the luteal phase in the outcome of assisted reproduction cycles.

The effect of long-acting GnRHa, in the luteal phase, during ART cycles varies from one patient to another. The aim of this study was to evaluate whether the effect of long-acting GnRHa in the luteal phase, in ART cycles, affects pregnancy rates according to the duration of its action in such phase. This is a retrospective study of 367 patients submitted to ovulation induction for in vitro fertilization/intracytoplasmic sperm injection procedures that used long-acting depot GnRHa for pituitary suppression. Patients were stratified according to the period of action of the agonist in the luteal phase: group 1, ≤ 6 days; group 2, 7 to 12 days; and group 3, >12 days. The following variables were analyzed: ovarian response, age, infertility causes and pregnancy rates. Group 1 (n = 53) had a mean age of 33.8 ± 4.55 years (23-44 years) and a pregnancy rate of 45.2%. In group 2 (n = 118), mean age was 33.7 ± 4.5 years (24-44 years) and the pregnancy rate was 38.9%. In group 3 (n = 196), mean age was 33.7 ± 4.4 years (23-43 years) and the pregnancy rate was 47.4%. Regardless of the duration of depot GnRHa action in the luteal phase, no significant association with pregnancy rates was found.