Contribution of fetal/maternal incompatibility to aetiology of pre-eclamptic toxaemia.

Data are presented on an association between toxaemia of pregnancy and consanguinity of patients, seen at a Turkish hospital, and their husbands. Women with toxaemia were less frequently related to their husbands than those with no signs of pre-eclampsia. The relationship between toxaemia in twin pregnancies and the sexes of the twin pairs from four sources are examined. In all four pre-eclampsia seems to be more common in unlike-sex than in like-sex twin pregnancies, and, by extension, to be more common in dizygous than in monozygous twin pregnancies.