Endocrinology: Reduced implantation rate associated with a subtle rise in serum progesterone concentration during the follicular phase of cycles stimulated with a combination of a gonadotrophin-releasing hormone agonist and gonadotrophin

Our objective was to assess the effects of subtle increasesin serum progesterone concentration (1.0–2.0 ng/ml) onthe outcome of in-vitro fertilization (IVF), particularly onthe quality of embryos, during the follicular phase of cyclesstimulated with gonadotrophin-releasing hormone agonist (GnRHa)and human menopausal gonadotrophin (HMG). A total of 97 patientsunderwent 116 cycles of IVF and were stimulated with a combinationof HMG and GnRHa. They were divided into two groups: those witha subtle progesterone rise and those with no progesterone rise.The two groups were compared with respect to serum oestradiol,progesterone, immunoreactive luteinizing hormone (I-LH), bioactiveLH (B-LH), and results of IVF. The groups did not differ significantlyin mean age or in total dose of HMG received. On the day thathuman chorionic gonadotrophin was administered, concentrationsof oestradiol and progesterone were significantly higher inthe subtle progesterone rise cycles than in the no progesteronerise cycles. In the no progesterone rise cycles, the percentagesfor embryos beyond the 4-cell stage, grade 1 embryos, and implantationrates were significantly higher than those in subtle progesteronerise cycles. The combination of GnRHa and HMG eliminated anysignificant rise in serum I-LH or B-LH concentration duringthe follicular phase, but did not suppress the subtle rise inprogesterone. These results confirm our previous finding thata subtle progesterone rise adversely affects the outcome ofIVF. It is also suggested that a reduction in embryo qualitymay influence the lower rate of implantation in subtle progesteronerise cycles.