The impact of risk factors on aspirin's efficacy for the prevention of preterm birth
Community Health Sciences
Background: The ASPIRIN Trial was a landmark study that demonstrated a reduction in preterm birth (PTB) and hypertensive disorders of pregnancy (HDP) in nulliparous women who received low-dose aspirin (LDA). All women in the study had at least one moderate-risk factor for preeclampsia, nulliparity. Unlike current United States Preventative Service Task Force (USPSTF) guidelines, which recommend LDA for two or more moderate-risk factors, women in this study were randomized to receive LDA regardless of the presence or absence of an additional risk factor.
Objective: To compare how low-dose aspirin (LDA) differentially benefits nulliparous women with and without additional preeclampsia risk factors for the prevention of preterm birth (PTB) and hypertensive disorders of pregnancy (HDP).
Study design: This is a non-pre-specified secondary analysis of the ASPIRIN trial that randomized nulliparous women with singleton pregnancies from six low-middle income countries to receive LDA or placebo. Our primary exposure was having an additional preeclampsia risk-factor beyond nulliparity. Our primary outcome was PTB before 37 weeks and our secondary outcomes included PTB before 34 weeks, PTB before 28 weeks, HDP, and perinatal mortality.
Results: Among 11,558 nulliparous women who met the inclusion criteria, 66.8% had no additional risk factors. LDA similarly reduced the risk of PTB (RR 0.75 vs. 0.85, p=0.35). Additionally for our secondary outcomes, LDA similarly reduced the risk of PTB <28 >weeks, HDP, and perinatal mortality in women with and without additional risk factors. The reduction of PTB (RR 0.69 vs. 1.04, p=0.04).
Conclusion: LDA's ability to prevent PTB, HDP, and perinatal mortality is similar in nulliparous women with and without additional risk factors. Professional societies should consider recommending LDA to all nulliparous women
Publication ( Name of Journal)
American Journal of Obstetrics & Gynecology MFM
Nuss, E. E.,
Hoffman, M. K.,
Goudar, S. S.,
(2023). The impact of risk factors on aspirin's efficacy for the prevention of preterm birth. American Journal of Obstetrics & Gynecology MFM.
Available at: https://ecommons.aku.edu/pakistan_fhs_mc_chs_chs/1095