Effect of delayed initiation of gonadotropin in luteal long protocol on in vitro fertilization

To evaluate whether delayed initiation of gonadotropin in luteal long protocol affected the outcome of in vitro fertilization (IVF).

Prospective randomized study at the reproductive centre of a university-based hospital. Eighty-five subfertile women undergoing IVF embryo transfer after a standardized gonadotropin-releasing hormone agonists (GnRHa) long protocol. The patients were randomized into group A (stimulated 3 weeks after GnRHa administration) and group B (stimulated 2 weeks after GnRHa administration), according to the time of gonadotropin initiation after GnRHa-mediated pituitary suppression. The main outcome measures were clinical pregnancy and live birth rates.

There were no significant differences in baseline characteristics such as age, body mass index and basal follicle-stimulating hormone (bFSH) between the two groups. In group B, the days of gonadotropin stimulation were significantly greater than that in group A (p < 0.05), while the total dose of gonadotropin in group A was comparable to that in group B. Serum luteinizing hormone was lower and follicle-stimulating hormone higher in group A than in group B (p < 0.05) on initiation day. There were no significant differences in hormone profile measurements between the two groups. Moreover, the clinical pregnancy rate, implantation rate, live birth rate, miscarriage rate and moderate ovarian hyperstimulation syndrome rate were not significantly different between the groups.

Delay of gonadotropin stimulation in a standard long protocol may increase clinical efficiency, without significantly changing clinical outcome.