Trophoblast production of hCG and ahCG from normal and abnormal pregnancies.

This study was designed to correlate early pregnancy outcome with serum and trophoblastic culture media levels of hCG, alpha hCG, and the alpha hCG/hCG ratio. Maternal serum was obtained from 104 women with normal gestations (n = 25), ectopic pregnancies (n = 43) and spontaneous abortions (n = 36); trophoblastic tissue was obtained from 10 subjects in each group. The alpha hCG/hCG ratio was abnormally elevated in the serum of 46% of women with abortions and 26% of those with ectopic pregnancies. Tissue culture experiments confirmed the relative increase in alpha hCG levels. Deteriorating trophoblast tissue from compromised or poorly oxygenated placental implantations results in abnormally elevated alpha hCG/hCG ratios; this occurs secondary to a greater relative decrease in hCG than alpha hCG production. The clinical utility of this knowledge is under investigation.