The role of early post-implantation beta-HCG levels in the outcome of pregnancies following in-vitro fertilization.

Daily plasma beta-HCG levels from days 11 to 18 after ovum retrieval (OR) were evaluated in a group of 73 women who became pregnant following in-vitro fertilization and embryo replacement (IVF-ER). The 47 patients who had a normal ongoing pregnancy could be distinguished from the 26 patients with a pathological pregnancy (pre-clinical abortion, clinical abortion and tubal pregnancy) by the mean daily beta-HCG levels, their mean daily increase and the intercept and slope of the beta-HCG regression analysis. The mean daily beta-HCG levels of the normal pregnancies were significantly higher than: (i) pre-clinical abortions on days 12-18 after OR; (ii) clinical abortions on days 12-16; and (iii) tubal pregnancies on days 12-17. Using quadratic discriminant analysis, normal and pathological pregnancies could also be distinguished by their absolute beta-HCG levels on day 13 after OR with 27.6 mIU/ml being the cut-off point. Our results indicate that the outcome of pregnancy following IVF-ER could be predicted with a high degree of probability by monitoring daily beta-HCG levels within the first 2 weeks following OR.