At this point, we've likely all encountered a patient who is on aspirin as a preventative for a history of pre-eclampsia or high risk pregnancy, but what about for low risk patients who have not yet had any children?
This meta-analysis came out in August of this year looking at RCTs that examined giving low dose aspirin to low-risk (no pre-eclampsia, gestational DM/HTN, autoimmune or renal disease), nulliparous individuals during pregnancy and found that while not all doses of aspirin at all ages were helpful, a planned subgroup analysis showed that giving 100mg of aspirin daily starting before 16 weeks cut the odds of preterm birth before 37 weeks in about half (RR 0.45).
That's not to say that we should all be starting aspirin for our patients in the emergency department just yet - but this might be why you're seeing aspirin pop up on more of our pregnant patients' medication list (or why your OB might be recommending it to you or your family/friends).
References
Wodoslawsky S, Khanuja K, Saccone G, Hoffman MK, Berghella V. Low-dose aspirin use in low-risk nulliparous pregnancies: a systematic review and meta-analysis of randomized controlled trials. Am J Obstet Gynecol MFM. 2025;7(2):101595. doi:10.1016/j.ajogmf.2024.101595
