Premature birth is the main cause of neonatal death and disease. Women with previous history of premature births have an increased risk of premature birth in subsequent pregnancy. Low-dose aspirin reduces the risk of premature birth in women at risk of preeclampsia, but it is not clear whether low-dose aspirin reduces the risk of recurrent premature birth. Recently, the journal Am J Obstet Gynecol published a study aimed at evaluating the relationship between low-dose aspirin and premature birth in women with a previous history of premature birth.
Study Overview
Investigators conducted an cohort study based on the Swedish registry, which included women who had two pregnancy periods between 2006 and 2019, with the first premature birth (with medical indications or spontaneous premature birth at 37 weeks of gestation). The study evaluated the association between low-dose aspirin use and second premature birth by standardized logistic regression models.
Study Results
In the study cohort (N=22,127), 3057 women (14%) took low dose aspirin at the second pregnancy, and 3703 women (17%) had premature birth. Results showed that:
➤ The use of low-dose aspirin was correlated with a reduced risk of premature birth (marginal relative risk [mRR] 0.87 95% CI 0.77-0.99).
➤ There was no statistically significant association between the use of low-dose aspirin and the risk of changing with moderate premature birth (defined as birth at 32-36 weeks of pregnancy; mRR 0.90 95% CI 0.78-1.03) or extremely premature birth (defined as birth at 32-week gestation; mRR 0.75 95% CI 0.54-1.04).
➤ Regarding the occurrence of premature birth, the use of low-dose aspirin was associated with a reduced risk of spontaneous premature birth (mRR 0.70 95% CI 0.57-0.86), but did not reduce the risk of medically indicated premature birth (mRR 1.09 95% CI 0.91-1.30).
Study Conclusion
In women with a history of premature birth, the use of low-dose aspirin is associated with reducing the risk of premature birth. When premature birth is observed in the second pregnancy, the use of low-dose aspirin is associated with a reduced risk of spontaneous premature birth. The results of this study suggest that low doses of aspirin may be an effective preventive measure for recurrent premature birth.
Yimaitong compiled from: Kupka EJ, Hesselman S, Hastie R, Lomartire R, Wikström AK, Bergman LS. Low-dose aspirin use in pregnancy and the risk of preterm birth: a Swedish register-based cohort study. Am J Obstet Gynecol. 2022 Sep 9:S0002-9378(22)00728-1. doi: 10.1016/j.ajog.2022.09.006. Epub ahead of print. PMID: 36096185.
