Human chorionic gonadotropin and its subunits in pre-eclampsia

The serum levels of hCG and its subunits were studied in 11 cases of pre-eclampsia (8 cases of severe pre-eclampsia and 3 cases of mild pre-eclampsia) and 72 normal pregnant women. The hCG (human chorionic gonadotropin) immunoactivity measured by H80 RIA (radioimmunoassay) and Sb6 RIA showed no significant difference between pre-eclampsia and normal pregnancy. This result suggests that no significant amount of free hCG-beta existed, since H80 RIA measured intact hCG but not hCG-beta, and Sb6 RIA measured both hCG and hCG-beta. Furthermore, from the result of elution behavior of gel HPLC (high performance liquid chromatography), hCG of pre-eclampsia and comparison of the Sb6 RIA/H80 RIA ratio between pre-eclampsia and normal pregnancy, it was evident that there was little amount of free hCG-beta secretion in pre-eclampsia as in normal pregnancy. However, the free hCG-alpha was significantly higher in severe pre-eclampsia, probably caused by placental dysfunction. In summary, free hCG-alpha is increased in pre-eclampsia, but its role as a marker of placental function in pre-eclampsia requires further investigation.