The effect of progesterone supplementation prior to the induction of ovulation in women treated for in-vitro fertilization.

Thirty-one patients superovulated with clomiphene citrate (CC) and human menopausal gonadotrophin (HMG) were given a single injection of 25 mg progesterone (P group) 6 h prior to injection of human chorionic gonadotrophin (HCG). Levels of urinary and plasma luteinizing hormone (LH) were significantly higher (P less than 0.001) immediately prior to HCG in the P group compared with thirty-one control patients who had HCG on the same night. Plasma levels of progesterone remained significantly elevated (P less than 0.02) for 80 h after injection in the P group, thereafter the level was similar to controls. The number of oocytes recovered, fertilized and replaced per patient was identical in both groups. However, four control patients had no embryos replaced due to failed fertilization. It is concluded that in the majority of P patients the timing of ovulation induction by HCG injection was appropriate as an LH surge was elicited thus reflecting a physiological stage of readiness, and elevated plasma progesterone levels around the time of oocyte recovery and in the early luteal phase do not increase the likelihood of the establishment of pregnancy in patients stimulated for in-vitro fertilization and embryo replacement (IVF/ER) with CC and HMG.