Luteal support after luteinizing hormone-releasing hormone agonist for in vitro fertilization: superiority of human chorionic gonadotropin over oral progesterone.

It has been reported that the pregnancy rate after in vitro fertilization (IVF) after pituitary desensitization with luteinizing hormone-releasing hormone agonist (LH-RH-a) is twice as low if the luteal phase is not supported. We therefore tested the respective advantages of luteal support using human chorionic gonadotropin (hCG, 1,500 IU three times) and progesterone (P, micronized, oral administration, 400 mg/d) after 171 embryo transfers (ET) in which the cycle was stimulated with the LH-RH-a triptoreline. The type of luteal phase support was randomly selected except when the estradiol level exceeded 2,700 pg/mL. The clinical pregnancy rate and the ongoing pregnancy rate were significantly higher using hCG (after the transfer of 3 embryos, 45% and 43% with hCG versus 23% and 17% with P). The same results were noted for the embryo implantation rate per ET (19% of embryos are viable after 6 months of pregnancy after hCG versus 7.5% after P). Adequate luteal support, therefore, significantly improves the results of IVF when LH-RH-a are used. The poor results obtained with P in this study might be related to its poor bioavailability after oral administration.