Is factor XII deficiency related to recurrent miscarriage?

Factor XII (FXII) is an important protease that plays a major role in the i nitiation of the intrinsic pathway of blood coagulation. Although congenita l FXII deficiency is not associated with a clinical bleeding tendency, it c an be identified on a routine coagulation test, such as a prolonged activat ed partial thromboplastin time. This deficiency is a rare autosomal recessi ve disorder. It is still unclear whether FXII deficiency causes any disorde rs during pregnancy. Recurrent miscarriages and placental abruption were re ported in cases with FXII deficiency. We successfully treated a woman whose pregnancy was complicated by congenital FXII deficiency. We report her cli nical courses of gestation, delivery, and puerperium and discuss the role o f maternal FXII associated with pregnancy. In our case, courses of gestatio n and delivery were normal. Postpartum uterine bleeding was, however, prolo nged due to a subinvolution of the puerperal uterus. Our results indicate t hat, except for postpartum uterine contraction, FXII does not play a major role in gestation and delivery. We suggest that FXII deficiency is not asso ciated with recurrent miscarriage and that normal gestation and vaginal del ivery are possible even in cases with congenital FXII deficiency. We assert that the possible correlation of FXII deficiency with recurrent miscarriag e merits reevaluation.