title: The impact of low-dose aspirin on preterm birth: secondary analysis of a randomized controlled trial.
abstract: The objective of this study is to determine whether low-dose aspirin (LDA) reduced the rate of preterm birth (PTB) in a cohort of women at high risk for preeclampsia.
  
  
  
  Secondary analysis of the Maternal-Fetal Medicine Units High-Risk Aspirin trial. Preterm births were categorized by phenotype: indicated, spontaneous or due to preterm premature rupture of membranes (PPROMs).
  
  
  
  Of 1789 randomized women, 30.5% delivered before 37 weeks (18.5% indicated, 5.8% spontaneous and 6.2% following preterm PPROMs). Among women randomized to LDA, we observed a trend favoring fewer PTBs due to spontaneous preterm labor and preterm PPROMs, odds ratio (OR: 0.826 (0.620, 1.099)); the incidence of indicated PTBs appeared unchanged, OR: 0.999 (0.787, 1.268).
  
  
  
  Although not reaching significance, we observed an effect size similar to other studies of both low- and high-risk women. These results support findings from other studies assessing LDA as a PTB prevention strategy.
authors.affiliation: University of Colorado School of Public Health, Aurora, CO, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Allshouse
authors.affiliation: Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, CO, USA.
authors.forename: R H
authors.initials: RH
authors.lastname: Jessel
authors.affiliation: Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, CO, USA.|Department of Obstetrics and Gynecology, Denver Health and Hospital Authority, Denver, CO, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Heyborne
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects; D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000517:prevention & control*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D010043:Outcome and Process Assessment, Health Care; D011225:Pre-Eclampsia / Q000517:prevention & control*; D011247:Pregnancy; D047928:Premature Birth / Q000517:prevention & control*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin