Postnatal screening for thrombophilia in women with severe pregnancy complications

To examine the prevalence of maternal thrombophilia in women with severe preeclampsia/eclampsia, placental abruption, fetal growth restriction, and unexplained stillbirth.

We studied 102 women who had pregnancy complications and 44 healthy women with uncomplicated pregnancies. All women were tested 10 weeks postpartum for mutations of factor V Leiden, methylenetetrahydrofolate reductase (MTHFR) C677T, and G20210A prothrombin gene; deficiencies of protein C, protein S, and antithrombin III; and the presence of lupus anticoagulant and anticardiolipin antibodies. We aimed to recruit 100 cases and 300 controls to detect a 10% difference in thrombophilia between the groups. However, we were able to recruit only 44 controls.

Abnormal thrombophilia screen was found in 54 women with pregnancy complications (53%) and in 17 women (39%) with normal pregnancies (odds ratio [OR] 1.8; 95% confidence interval [CI] 0.87, 3.67). Mutations encoding for factor V Leiden, G20210A prothrombin gene, and MTHFR C677T (homozygous) were identified in 18% of women with complications compared with 16% of controls (OR 1.1; 95% CI 0.44, 2.94). Activated protein C resistance, not due to factor V Leiden mutation, was the most common thrombophilic defect, found in 26% of women with pregnancy complications compared with 18% of controls (OR 1.5; 95% CI 0.63, 3.73). Twenty women with complications (20%) had multiple thrombophilic defects compared with four controls (9%) (OR 2.4; 95% CI 0.78, 7.61).

In our cohort of women with pregnancy complications, maternal thrombophilia was less common than previously thought, and multiple thrombophilias were not a major additional risk factor.