Alpha subunit and human chorionic gonadotropin in normal pregnancy and gestational trophoblastic disease.

The reported incidence of gestational trophoblastic disease is an order of magnitude higher in Nigeria than in the United States. Sera from a total of 283 pregnant black patients, 138 United States and 148 Nigerian pregnant patients, were analyzed for their serum levels of alpha subunit and human chorionic gonadotropin (hCG). The patterns of hCG secretion were similar in the two populations during normal pregnancy. However, the level of alpha subunit was persistently higher in Nigerian women than in comparable pregnant United States patients. A statistically significantly higher alpha subunit level in the Nigerian patients was found only in the ten- to 13-week gestational period (P less than .005). The higher level of alpha subunit in pregnancy in Nigerian women may signal a population of trophoblastic cells which may be at higher risk for malignancy development in the Nigerian woman.