Some endocrinological events associated with early pregnancy failure.

Serial measurements of serum progesterone, oestradiol, human chorionic gonadotrophin (hCG) and human placental lactogen (hPL) have been determined in 33 women experiencing early pregnancy failure and compared with the values of the same hormones in 72 healthy women having uncomplicated pregnancies. Steroid production by the corpus luteum seemed similar in both groups up to 6 weeks gestation but thereafter placental steroidogenesis was not evident in those women in whom spontaneous pregnancy losses occurred. Placental production of the two protein hormones, hCG and hPL, did take place, and whereas the circulating levels were not as high as in normal pregnancies, levels did usually increase before clinical evidence of miscarriage occurred. hCG was not a sensitive discriminator of subsequent failure. In these women there were no significant hormone differences between those with evidence of a fetus and those without.