Sex ratio of newborns: preponderance of males in toxemia of pregnancy.

The ratio of males to females in 1061 babies born to mothers with toxemia of pregnancy is 1.24. The ratio increases as the severity of the disease increases, being 1.71 in cases in which the urinary output of protein is equal to or greater than 3 grams per 24 hours. Histoincompatibility of the fetus and mother, including incompatibility due to an antigen (or antigens) dependent on the Y chromosome, is suggested to function in the pathogenesis of pregnancy toxemia.