Preeclampsia and fetal loss in women with a history of venous thromboembolism

A higher prevalence of risk factors for venous thromboembolism (VTE) has been found in women with preeclampsia and fetal loss. We investigated whether women with a history of VTE have a higher prevalence of pregnancy-associated complications compared with control subjects. In 395 patients with a history of VTE and in 313 control women, the prevalence of complications during pregnancy and the mean birth weight of viable infants were evaluated. The prevalence of pregnancy-induced hypertension and preeclampsia was higher in patients (5.1% and 3.0%, respectively) compared with control subjects (1.3% each). The odds ratio was 4.13 for pregnancy- induced hypertension (95% CI 1.4 to 12.22, P=0.0058) and 2.43 for preeclampsia (95% CI 0.78 to 7.6, P=0.133). Stillbirth was slightly more frequent in patients (4.3%) than in control subjects (3.2%); the difference was not statistically significant. Miscarriage was equally frequent in patients (21.8%) and control subjects (21.3%). The birth weight of viable infants born to patients was, on average, 109 g lower than that of the infants born to the control subjects (P=0.014) after adjustment for the mother's body mass index. Our study demonstrates that women with a predisposition to VTE have, overall, a good chance for a successful pregnancy outcome. However, the findings from our study support the assumption that a predisposition to venous thrombosis is associated with a higher risk for complications during pregnancy and lower infant birth weight.