Protocols for induction of ovulation. The concept of programmed cycles.

Programmed oocyte retrieval which includes suppression of the hypothalamic-pituitary-ovarian axis by oral contraceptives or GnRH analogue and predetermined ("fixed") day for ovum pick-up has been demonstrated to yield a pregnancy rate that is comparable to that achieved by the conventional individualized approach to follicular maturation. We have prospectively compared two regimens of suppression (the pill and GnRH analogue) followed by two ovarian stimulation protocols (clomiphene citrate + human menopausal gonadotropin [CC + hMG] and pure follicle-stimulating hormone + human menopausal gonadotropin [pure FSH + hMG]). Sixteen patients were studied in each group. It was found that the latent phase, which represents a period of ovarian insensitivity, was prolonged and directly correlated to the duration of suppression, and that suppression with the GnRH analogue was associated with a shorter latent phase than that with the pill. Suppression with the pill for 30 days compared with 15 days resulted in a greater cancellation of laparoscopic oocyte retrieval, a lower fertilization rate, and a lower pregnancy rate. The numbers of oocytes recovered, fertilized, and cleaved were similar in both stimulation protocols. The use of the GnRH analogue for 30 days compared with 15 days was associated with a lower pregnancy rate, even though the number of oocytes that were recovered and fertilized were similar. Ovarian stimulation with pure FSH + hMG resulted in a shorter latent phase than did stimulation with CC + hMG, but the results of treatment with both protocols were similar. It is concluded that both the pill and GnRH analogue are acceptable means of manipulating the cycle and the day of oocyte retrieval. However, they should be used for the shortest periods possible because prolonged use is associated with some unwarranted effects. For each suppression-stimulation protocol there seems to be a different fixed day for retrieval that should be established prospectively.