Table 1: Risk factors and their odds ratios (ORs) för VTE (1,2).

Prevalence (%)Pregnancy ORPostpartum OR

Overweight (BMI > 28)1
 >28 BMI12.855
Familial thrombosis (first-degree relatives)
 yes5.155
Age
 <202.51.02.5
 ≥20–<3585.21.01
 ≥3512.41.01.2
Smoking
 yes21.01.21.2
Parity
 Primapara41.32.31.1
 1 birth35.411
 2 births15.81.31.7
 >2 births7.32.61.8
Preeclampsia
 Yes2.03–5
Cesarean section
 Yes11.04.9
FV Leiden
 Noncarrier89.111
 Heterozygotes10.655
 Homozygotes0.325–10025–100
Protein S or protein C deficiency0.15–255–25
Prothrombin gene mutation2.055
Hyperhomocysteinemia 2–52–5

1BMI > mean + 1SD in early pregnancy is regarded as overweight.