Objective: The purpose of this study was to determine, on the basis of published reports, whether aspirin use during the first trimester of pregnancy is associated with an increased risk of congenital malformations.
Study design: We reviewed the literature for published studies that reported exposure to aspirin during the first trimester of pregnancy and congenital malformations. Two reviewers independently determined whether a study should be included in the final analysis and extracted the data. We calculated the pooled odds ratio and 95% CI.
Results: Twenty-two studies met the inclusion criteria. In the eight studies that reported an overall risk, the risk of congenital malformations in offspring of women who were exposed to aspirin was not significantly higher than that in control subjects (odds ratio, 1.33; 95% CI, 0.94-1.89). However, a significantly increased risk of gastroschisis (odds ratio, 2.37; 95% CI, 1.44-3.88) was found.
Conclusion: We found no evidence of an overall increase in the risk of congenital malformations that could be associated with aspirin. Aspirin exposure during the first trimester may be associated with an increased risk of gastroschisis.