ABSTRACT
BACKGROUND: Limited data exist on the risk of pregnancy-associated venous thromboembolism (VTE) in women with a history of VTE. OBJECTIVE: To evaluate the risk of recurrent pregnancy-associated thrombosis in women with previous VTE in a large retrospective cohort study. PATIENTS AND METHODS: One hundred and fifty-nine women with at least one pregnancy (293 pregnancies in total) after a VTE were included into the study. The patients underwent a standardized interview on their history of thrombosis and pregnancy-associated complications. RESULTS: Eight recurrent events occurred during 197 pregnancies without thrombosis prophylaxis. The probability of VTE during pregnancy without thrombosis prophylaxis was 6.2% (95% confidence interval 1.6-10.9%). The risk was constant over the whole period of pregnancy. Of the eight women with VTE during pregnancy four had heterozygous FV:R506Q, two in combination with hyperhomocysteinemia. No VTE occurred during 87 pregnancies with thrombosis prophylaxis. In the postpartum period 15 VTEs occurred, two of 83 (2.4%) after pregnancy termination, one of 53 (1.9%) after miscarriage, three of 10 (30%) after stillbirth and nine of 138 (6.5%) after live birth. CONCLUSIONS: Without thrombosis prophylaxis the risk for recurrent symptomatic VTE is substantial during the whole period of pregnancy in women with previous VTE. The majority of events occurred after delivery, reflecting the very high risk during the postpartum period. Prospective and comparative trials to ascertain efficacy and safety of prophylactic heparin are urgently needed.
Subject(s)
Pregnancy Complications, Cardiovascular , Thromboembolism/diagnosis , Thromboembolism/prevention & control , Venous Thrombosis/diagnosis , Venous Thrombosis/prevention & control , Adolescent , Adult , Blood Coagulation Tests , Cohort Studies , Factor V/genetics , Female , Heparin/pharmacology , Heparin, Low-Molecular-Weight/pharmacology , Heterozygote , Humans , Hyperhomocysteinemia/genetics , Models, Biological , Pregnancy , Pregnancy Outcome , Risk , Risk Factors , Time FactorsABSTRACT
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.
