Pregnancy complications in women with inherited thrombophilia

Objective: The purpose of this study was to examine whether women with inherited thrombophilia have an increased risk of developing pregnancy complications. Methods: All singleton pregnancies with known inherited thrombophilia were compared to those without inherited thrombophilia for deliveries during the years 2000–2002 in a tertiary medical center. Data regarding inherited thrombophilia (International Classification of Disease 9th revision, Clinical Modification code 286.3) were available from the perinatal database in our center. Women lacking prenatal care were excluded from the analysis. Stratified analysis, using a multiple logistic regression model, was performed to control for confounders. Results: Out of 32,763 singleton deliveries that occurred during the study period, 0.2% (n=57) of the women were diagnosed with inherited thrombophilia. Using a multivariate analysis, with backward elimination, the following conditions were significantly associated with inherited thrombophilia: previous fetal losses [odds ratio (OR)=5.5; 95% confidence interval (CI) 2.9–10.3; P<0.001], recurrent abortions (OR=9.5; 95% CI 5.5–16.3; P<0.001), fertility treatments (OR=3.7; 95% CI 1.3–10.6; P=0.014), and intrauterine growth restriction (OR=7.2; 95% CI 3.4–15; P<0.001). Perinatal mortality was significantly higher in women with inherited thrombophilia than in those without known thrombophilia 5.3% (3/57) versus 0.6% (477/32,763) P=0.017. However, inherited thrombophilia was not found to be an independent risk factor for perinatal mortality (OR=3.05; 95% CI 0.90–10.3; P<0.073) in a multivariate analysis with perinatal mortality as the outcome variable, controlling for recurrent abortions, IUGR, and gestational age. Conclusion: Inherited thrombophilia, associated with previous fetal losses, recurrent abortions, fertility treatments, and intrauterine growth restriction, was not an independent risk factor for perinatal mortality.