Factor XII deficiency is strongly associated with primary recurrent abortions.

OBJECTIVE: To evaluate factor XII deficiency in women with primary and secondary recurrent abortion.

DESIGN: Prospective case-control study.

SETTING: University hospital.

PATIENT(S): Sixty-seven women with primary and 33 women with secondary recurrent abortion of unexplained nature and 49 healthy controls with no history of thrombotic disease or adverse pregnancy outcomes. MAIL OUTCOME MEASURE(S): Plasma factor XII activity, activated protein C resistance, factor V Leiden mutation analysis, protein C, protein S, antithrombin III, karyotyping, and anticardiolipin antibodies.

RESULT(S): Ten of 67 women with primary recurrent abortion (14.9%) and 4 of 33 women (12.1%) with secondary recurrent abortion had reduced factor XII activity (<60%). These results are highly significant in the former group and showed a tendency toward significance in the latter group. All controls had normal factor XII activity.

CONCLUSION(S): Factor XII deficiency is strongly associated with primary recurrent abortion, and women with secondary recurrent abortion show a tendency toward factor XII deficiency.