Postnatal screening for thrombophilia in women with severe pregnancy complications.

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