Hyperandrogenic states in pregnancy are almost always the result of a condition that arises during pregnancy. The onset of virilization symptoms is often very fast. The mother is protected against hyperandrogenism by a high level of SHBG, by placental aromatase and a high level of progesterone. The fetus is protected from the mother’s hyperandrogenism partly by the placental aromatase, that transforms the androgens into estrogens, and partly by SHGB. Nevertheless there is a significant risk of virilization of the female fetus if the mother’s hyperandrogenic state is serious. The most frequent cause of hyperandrogenic states during pregnancy are pregnancy luteoma and hyperreactio luteinalis. Hormonal production is evident in a third of all luteomas, which corresponds to virilization in 25-35 % of mothers with luteoma. The female fetus is afflicted with virilization with two thirds of virilized mothers. Hyperreactio luteinalis is created in connection with a high level of hCG, e.g. during multi-fetus pregnancies. This condition most frequently arises in the third trimester, virilization of the mother occurs in a third of cases. Virilization of the fetus has not yet been described. The most serious cause of hyperandrogenism is represented by ovarian tumors, which are fortunately rare.