Background: To evaluate the effect of low-dose aspirin in prevention of adverse pregnancy outcomes (APO) in women with second trimester alpha-fetoprotein (AFP) >2.5 multiple of median (MOM) and to compare aspirin effect on women with normal and abnormal uterine artery (UtA) Doppler. The primary outcome was the adverse pregnancy outcome.
Methods: This randomized controlled trial was conducted in singleton pregnant women, who had unexplained AFP >2.5 MOM and gestational age between 15 and 18 weeks of gestation. They were assigned randomly to receive either aspirin (N = 65) or control (N = 68). UtA Doppler velocimetry studies were performed at the time of targeted ultrasonographic exam.
Results: Two groups were comparable regarding the maternal characteristics. The frequency of APO in aspirin and control groups were 26.1% versus 44.1% (p = 0.045), the frequency of preterm delivery before 34 weeks were 3.2% versus 22.0% in aspirin and control group, p = 0.001. Other outcomes were similar in both groups. The frequency of adverse outcomes in women with abnormal UtA Doppler was 39.1% in aspirin and 60.0% in control group, p = 0.556.
Conclusion: Low-dose aspirin reduces APO and delivery before 34 weeks of gestation in pregnant women with unexplained elevated AFP.