PROGESTERONE ALONE VERSUS PROGESTERONE COMBINED WITH HCG AS LUTEAL SUPPORT IN GNRHA HMG INDUCED IVF CYCLES - A RANDOMIZED CLINICAL-TRIAL/

Two different regimens of luteal support in gonadotrophin hormone-rele asing hormone (GnRH) analogue/human menopausal gonadotrophin (GnRHa/HM G)-induced in-vitro fertilization cycles (IVF) were compared in a rand omized clinical trial. After embryo transfer, either vaginal progester one alone was administered (n = 89, P group), or a combination of vagi nal progesterone and human chorionic gonadotrophin (n = 87, P/HCG grou p). The primary aim of this study was to assess the effect of the diff erent regimens of luteal support on the pregnancy rate. The secondary aim was to compare oestradiol and progesterone concentrations in the l uteal phase between the two groups, and assess their effect on the pre gnancy rate. A clinical pregnancy rate of 15% was found in the P/HCG g roup in comparison with 26% in the P group (odds ratio 0.49; 99% confi dence interval: 0.18-1.3), The luteal serum oestradiol and progesteron e values in the P/HCG group were significantly higher when compared wi th the P group on the 6th, 9th and 12th day after oocyte retrieval (Wi lcoxon P <0.001). In accordance with the high oestradiol concentration s, more cases of ovarian hyperstimulation syndrome (OHSS) were found i n the P/HCG group, Oestradiol values on the 9th day after oocyte retri eval, presumably the day of implantation, appeared to be higher in wom en who did not become clinically pregnant. We conclude that vaginal pr ogesterone alone provides sufficient luteal support in GnRHa/HMG induc ed IVF cycles. The combination of vaginal progesterone and HCG as lute al support leads to significant high luteal oestradiol and progesteron e concentrations, But a high concentration of oestradiol seems to have a deleterious effect on the implantation process, resulting in a low pregnancy rate.