LUTEAL PHASE SUPPORT IN INVITRO FERTILIZATION USING GONADOTROPIN-RELEASING-HORMONE ANALOG BEFORE OVARIAN STIMULATION - A PROSPECTIVE RANDOMIZED STUDY OF HUMAN CHORIONIC-GONADOTROPIN VERSUS INTRAMUSCULAR PROGESTERONE

This study was conducted to compare the endocrine milieu and pregnancy rates in an in-vitro fertilization and embryo transfer (IVF-ET) programme employing a gonadotrophin-releasing hormone agonist (GnRHa) and human menopausal gonadotrophin (HMG) when either human chorionic gonadotrophin (HCG) or progesterone were used for luteal phase support. A total of 121 IVF - ET treatment cycles were prospectively studied. All patients started leuprolide acetate in the midluteal phase and it was continued for at least 10 days. When oestradiol levels were < 150 pmol/l, HMG was started. When at least three follicles were greater-than-or-equal-to 17 mm in diameter, HCG 5000 IU i.m. was given. Oocytes were retrieved using transvaginal ultrasound and embryos were transferred 48 h later. The patients' cycles were prospectively randomized to receive HCG (72 cycles) or progesterone (49 cycles) luteal support. The HCG group received 1500 IU i.m. on days 3, 6 and 9 after the initial trigger. The progesterone group received 12.5 mg i.m. q.d. starting from the day after the HCG trigger. The dose of progesterone was increased to 25 mg i.m. q.d. starting on the day of embryo transfer and continued for 17-21 days. If the patient became pregnant, this dose of progesterone was continued until fetal heart activity was visualized by ultrasound. Mean ages, number of eggs retrieved, embryos transferred, oestradiol levels on the day of the HCG trigger, oestradiol and progesterone at the time of embryo transfer were the same in both groups. However, 9 days after the HCG trigger, the HCG group had significantly higher oestradiol, progesterone and a lower oestradiol/progesterone ratio than the progesterone group (P <0.001). Furthermore, progesterone levels 9 days after HCG fell in the progesterone group, but rose in the HCG group (P < 0.0001). The total pregnancy rate (sac visible on ultrasound) in the HCG group was 18% (13/72) and in the progesterone group 17% (7/49). There were three miscarriages in the HCG and one in the progesterone group together with two ectopic pregnancies. Liveborn delivered rates were 14% (10/72) in the HCG group and 8% (4/49) in the progesterone group (NS). There appears to be a superior endocrine milieu in the HCG group compared with the progesterone group but our numbers are too small to demonstrate a difference in pregnancy rates between groups.