Pregnancy outcome of patients following deep venous thrombosis

Objective. To investigate pregnancy outcome of patients with a history of deep vein thrombosis DVT. Methods. A population-based study comparing all pregnancies of patients with and without a history of DVT was conducted. Deliveries occurred during the years 19882007 at a tertiary Medical Center. Stratified analyses were performed using multivariable logistic regression models and the Mantel-Haenszel technique. Results. During the study there were 212,086 deliveries, of which 122 0.06 occurred in patients with a history of DVT. Using a multivariate analysis, with backward elimination, the following conditions were significantly associated with DVT: advanced maternal age OR, 1.1; 95 CI, 1.021.1; p 0.004, chronic hypertension OR, 2.9; 95 CI, 1.46.0; p 0.005 and previous caesarean delivery OR, 2.8; 95 CI, 1.94.1; p < 0.001. Patients with a history of DVT were more likely to have caesarean deliveries OR, 2.6; 95 CI, 1.83.8; p < 0.001 than non-DVT patients. After controlling for possible confounders, such as maternal age, hypertensive disorders, pregestational diabetes and multiple gestations, by using another multivariate analysis with preterm delivery <37 weeks' gestation as the outcome variable, DVT was found to be an independent risk factor for preterm birth OR, 1.8; 95 CI, 1.12.9; p 0.033. This association remained significant after controlling for labor induction, using the Mantel-Haenszel technique OR, 1.8; 95 CI, 1.13.0; p 0.011. No significant differences were noted between the groups regarding perinatal outcomes such as low Apgar scores, congenital malformations or perinatal mortality. Conclusions. A history of DVT is an independent risk factor for spontaneous preterm delivery. Nevertheless, in our population it is not associated with adverse perinatal outcome.