IS LUTEAL FUNCTION MAINTAINED BY FACTORS OTHER THAN CHORIONIC-GONADOTROPIN IN EARLY-PREGNANCY

Women with ectopic pregnancy (n = 14) and early embryonic arrest ('bli ghted ovum') (n = 9) were studied 16 days after conception, at a time when they were asymptomatic and serum concentrations of beta-human cho rionic gonadotrophin (HCG) were in the normal range and increasing at an apparently normal rate. Serum progesterone and oestradiol concentra tions were compared with those from normal women matched for gestation al age and serum beta-HCG concentration whose singleton intra-uterine pregnancies proceeded normally beyond 20 weeks. Mean serum progesteron e concentrations were significantly lower in the women with ectopic pr egnancies than in matched controls (P < 0.002); however, there was no difference in the serum progesterone concentrations between women with blighted ova and matched controls. Statistically significant differen ces were not seen in serum oestradiol concentrations between either gr oup and matched controls. Similarly there was no difference in serum p rogesterone or oestradiol concentrations in 20 women who conceived ect opic pregnancies and 20 women conceiving blighted ovum pregnancies and their matched intra-uterine controls when conception followed ovarian stimulation. The low serum progesterone concentrations seen in ectopi c pregnancy suggest that there is a specific and selective deficiency in progesterone synthesis, which implies that factors other than HCG m ay influence luteal function.