Prospective, Randomized, Controlled Study of In Vitro Fertilization–Embryo Transfer With a Single Dose of a Luteinizing Hormone–Releasing Hormone (LH-RH) Antagonist (Cetrorelix) or a Depot Formula of an LH-RH Agonist (Triptorelin)

Abstract

The medical hypophysectomy produced by LH-RH agonists prevents premature LH surges, cancelling the cycle and leading to a poor outcome of in vitro fertilization (IVF). These agents do permit treatment cycles to be programmed, but side effects from hormonal depletion can be a problem, and desensitization usually requires 2 to 3 weeks. LH-RH antagonists lack these side effects and rapidly decrease gonadotropin levels. This prospective multicenter study evaluated a single-dose regimen of the LH-RH antagonist cetrorelix for preventing premature LH surges, comparing it with a depot preparation of triptorelin, a LH-RH agonist. Infertile women aged 18 to 39 years who were undergoing ovarian stimulation for IVF–embryo transfer, with or without intracytoplasmic sperm injection, were randomly assigned to receive a single 3-mg dose of cetrorelix (115 patients) during the late follicular phase or 3.75 mg of the depot preparation of triptorelin during the midluteal phase before the stimulation cycle (39 patients). A premature LH surge was defined as a concentration >10 IU/liter followed by an increase in progesterone to at least 1 ng/ml. Subsequent doses of cetrorelix were given to 10 percent of the women. None of these 115 patients had an LH surge after receiving the antagonist, although 3 with a high estrogen level did have a surge before treatment. The average duration of stimulation was significantly less with cetrorelix than with triptorelin (9.4 vs. 10.7 days). The average number of follicles measuring 18 mm or larger on the day of chorionic gonadotropin therapy was similar in the two groups, but follicles measuring ≥15 mm were more frequent in the triptorelin group. Total retrieved oocytes and mature or metaphase II oocytes were greater in the triptorelin group, as was the total number of embryos obtained. Ovarian hyperstimulation syndrome was diagnosed in 11 percent of this group and in 3.5 percent of women given cetrorelix. Clinical pregnancy rates were comparable, as were rates of ongoing pregnancy per embryo transfer (23 percent with cetrorelix and 27 percent with triptorelin). There were similar numbers of miscarriages in the two groups. A single dose of cetrorelix can prevent premature ovulation in women undergoing IVF–embryo transfer. The agent is well tolerated, and patient compliance is assured. Ovarian hyperstimulation is less of a risk than when administering a LH-RH agonist, and the outcome is similar. Fertil Steril 2000;73:314–320