Effect of Low-Dose Aspirin on Preeclampsia Incidence in High-Risk Pregnancies at Federal Teaching Hospitals in the North West

Low-dose aspirin prescribed from the first trimester is recommended for preeclampsia prevention in high-risk pregnancies, yet its consistent implementation and effectiveness in Nigerian tertiary hospital antenatal settings in the North West zone have not been empirically evaluated. This randomised controlled feasibility study examines the effect of low-dose aspirin (150 mg daily from 11 to 14 weeks) on preeclampsia incidence in high-risk pregnancies at Aminu Kano Teaching Hospital and UDUTH Sokoto. One hundred and twenty women with two or more high-risk factors (nulliparity, prior preeclampsia, multiple gestation, pre-existing hypertension, or diabetes) were randomised to aspirin or placebo from 11 to 14 weeks. Blood pressure, proteinuria, and foetal growth were monitored at four-weekly antenatal visits. Preeclampsia incidence by 34 weeks was 8.3 percent in the aspirin arm versus 21.7 percent in the placebo arm, representing a relative risk reduction of 62 percent (RR 0.38, 95% CI 0.14 to 0.98). Preterm preeclampsia before 37 weeks was entirely absent in the aspirin group. Aspirin tolerability was good, with no significant side effect differences between arms. The study provides North West zone randomised evidence supporting aspirin efficacy and recommends its integration into first-trimester antenatal protocols for high-risk women, with a risk factor screening tool deployed at first booking visit. Keywords: low-dose aspirin, preeclampsia prevention, high-risk pregnancy, North West Nigeria, randomised study