Do Abortions Increase the Risk of Blood Clots?

Induced abortion may increase a woman’s risk of venous thromboembolism (VTE), according to a recent study. Previous research has shown that women are at an elevated risk of VTE during pregnancy, however these studies have focused primarily on pregnancies that result in child birth. To evaluate the risk of VTE in woman who undergo induced abortion, researchers conducted a cohort study using data from the Canadian health-care system on 176,001 women whose first pregnancy concluded with induced abortion between 2003, and 2015. These women were compared with 176,001 women whose first pregnancy ended with child birth, and 880,005 women who were not pregnant. Women who were not between ages 15-49 were excluded from the study. Primary outcome was defined as the risk of VTE within 42 days of abortion, child birth, or induced abortion date of their matched counterpart (for the nonpregnant women).  

Researchers found that the rate of VTE in the induced abortion, nonpregnant, and child birth groups were 30.1, 13.5, and 184.7 per 100,000 women, respectively. These results show that the risk of VTE in women who have induced abortions is double that of those who are not pregnant, but is significantly lower than the risk in those who give birth to a child. From this information, physicians may find it more critical to consider testing for VTE in women who have recently had an abortion than in women who are not pregnant.  

Source: The Lancet