Maternal smoking, obesity, and risk of venous thromboembolism during pregnancy and the puerperium: a population-based nested case-control study.
BACKGROUND
Smoking and obesity are associated with adverse pregnancy outcomes. The aim of the present study was to examine the association between smoking, obesity (BMI>30), and risk for venous thromboembolism (VTE) during pregnancy and the puerperium.


METHODS
In a population-based case-control study nested within a Danish cohort of 71,729 women, we identified 129 cases with VTE in pregnancy or the puerperium, and 258 pregnant non-VTE controls. We obtained data from medical records regarding current smoking status, BMI, and other covariates, and computed the odds ratios (OR) for VTE as a measure of relative risk.


RESULTS
Smoking and obesity were associated with increased risk of VTE during pregnancy and the puerperium (adjusted OR 2.7 (95% CI: 1.5, 4.9) and 5.3 (95% CI: 2.1, 13.5), respectively). Obesity appeared to be associated with a higher risk of pulmonary embolism (adjusted OR: 14.9 (95% CI: 3.0, 74.8) than of deep venous thrombosis (adjusted OR: 4.4, 95% CI: 1.6, 11.9).


CONCLUSIONS
Smoking and obesity are risk factors for VTE in pregnancy and the puerperium.
Larsen
Torben Bjerregaard
TB
Department of Biochemistry, Pharmacology and Genetics, Odense University Hospital, Denmark. tblarsen@dadlnet.dk
Sørensen
Henrik Toft
HT
Gislum
Mette
M
Johnsen
Søren Paaske
SP
D016022:Case-Control Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D009035:Mothers; D009765:Obesity / Q000150:complications*; D016017:Odds Ratio; D044382:Population Groups; D049590:Postpartum Period; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D012306:Risk; D012907:Smoking / Q000009:adverse effects*; D013923:Thromboembolism / Q000453:epidemiology / Q000209:etiology*; D020246:Venous Thrombosis / Q000453:epidemiology / Q000209:etiology*