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. Author manuscript; available in PMC: 2022 Dec 1.
Published in final edited form as: Obstet Gynecol. 2021 Dec 1;138(6):945–946. doi: 10.1097/AOG.0000000000004612

Prediction and Prevention of Spontaneous Preterm Birth: ACOG Practice Bulletin, Number 234

Matthew K Hoffman 1
PMCID: PMC8607754  NIHMSID: NIHMS1745078  PMID: 34794160

I wish to thank the authors for their thoughtful review on the prediction and prevention of spontaneous preterm birth in the August 2021 issue.1 As the Practice Bulletin highlights, preterm birth remains among the largest challenges facing modern obstetrics with unfortunately worsening outcomes over the last several years within the United States.2

Though detailed and reasoned in its approach, I want to highlight one potential omission for further consideration, namely low-dose aspirin for the purpose of preventing preterm birth. Though not U.S. Food and Drug Administration–indicated for this purpose, greater than 48 randomized trials,3,4 including more than 47,00 pregnancies, have demonstrated that low-dose aspirin during pregnancy decreases the occurrence of preterm birth by approximately 10%. Similarly, these trials demonstrate that low dose aspirin during pregnancy decreases neonatal death or death before discharge by 15%.3 Inclusive of these studies are two large randomized trials of greater than 14,000 healthy nulliparous women that have demonstrated a significant(odds ratio [OR] 0.43, 95%CI 0.26–0.845 and OR 0.75–95%CI 0·61–0·934) reduction in early preterm birth(<34 weeks), which results in the majority of morbidity and mortality in children. This body of evidence makes low-dose aspirin one of the most studied interventions in obstetrics and has led other organizations such as the U.S. Preventive Services Task Force to highlight this benefit in its draft evidence review of aspirin in pregnancy.6

Though the association of low-dose aspirin with preeclampsia now spans more than 40 years, there is both clinical and biological evidence that there is substantial overlap between preterm birth and preeclampsia. Similarly, the above cited body of evidence suggests that low-dose aspirin is an effective preventive strategy for both. Though the Practice Bulletin specifically addresses spontaneous preterm birth, it should be noted that the cited literature does not specifically speciate out spontaneous preterm birth due to limitations of these studies. Nonetheless, given the now decades-long inability to improve preterm birth and neonatal death, and the large number of trials demonstrating both efficacy and safety, I believe it is now time to consider educating health care professionals about low-dose aspirin as a strategy for the prevention of preterm birth as well as preeclampsia.

Financial Disclosure

This letter references the ASPIRIN trial for Dr. Hoffman’s institution received travel support for the conduct of this work through the NICHD. Low-dose aspirin is not FDA approved and this is specifically noted.

REFERENCES

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