CAVEATS: Much of the data came from small studies
A substantial portion of the data in this systematic review and meta-analysis came from small studies with positive findings. Because small studies with null findings tend to not be published, there is concern that the results reported by Henderson et al1 may be somewhat biased, and that future studies may push the overall observed effect toward a null finding.
Also, the criteria used to define “high risk” for preeclampsia varied by study, so it’s unclear which groups of women would benefit most from aspirin use during pregnancy. Finally, there is a lack of high-quality data on the effects of aspirin use during pregnancy on long-term outcomes in children. Despite these caveats, the cumulative evidence strongly points to greater benefit than harm.
CHALLENGES TO IMPLEMENTATION: You need to determine which patients are at highest risk
The principle challenge lies in identifying which patients are at high risk for preeclampsia, and thus, will likely benefit from this intervention. This systematic review and meta-analysis used a large variety of risk factors to determine whether a woman was high risk. A 2013 American College of Obstetricians and Gynecologists Task Force on Hypertension in Pregnancy report defined high-risk as women with a history of preeclampsia in more than one previous pregnancy or women with a previous preterm delivery due to preeclampsia.4
The updated USPSTF recommendation suggests that women be considered high risk if they have any of the following: 1) previous preeclampsia, 2) multifetal gestation, 3) chronic hypertension, 4) diabetes, 5) renal disease, or 6) autoimmune disease.9 We consider both sets of criteria reasonable for identifying women who may benefit from low-dose aspirin during pregnancy.
ACKNOWLEDGEMENT
The PURLs Surveillance System was supported in part by Grant Number UL1RR024999 from the National Center For Research Resources, a Clinical Translational Science Award to the University of Chicago. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center For Research Resources or the National Institutes of Health.
