Beta-human chorionic gonadotropin as a monitor of pregnancy outcome in in vitro fertilization-embryo transfer patients.

Serum human chorionic gonadotropin (hCG) was studied to test its predictability of pregnancy outcome in in vitro fertilization (IVF) patients. The mean +/- standard deviation of serum hCG concentration related to the day complete clearance of exogenous hCG was derived from 47 single term pregnancies as a normal range. This range can be used to predict spontaneous abortion (77%), multiple pregnancy (60%), and abortion in multiple-sac pregnancies terminating in the birth of fewer infants than the initial number of sacs (80%). The results also showed that our stimulation protocol did not affect the clearance rate and doubling time of endogenous hCG or implantation time as suggested by the time of endogenous hCG detection and that spontaneous abortion may be due to late implantation.