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BACKGROUND: Pregnant women with sickle cell disease are at increased risk of intrauterine growth restriction (IUGR), pre-eclampsia, and sickle-related conditions. Low-dose aspirin might reduce some of these complications but has not been tested in sickle cell pregnancy. We aimed to investigate the effectiveness and safety of low-dose aspirin for preventing complications during pregnancy. METHODS: In a double-blind randomised controlled trial in 16 public health facilities in southwest Nigeria, pregnant women (aged ≥18 years) with haemoglobin SS (HbSS) or SC (HbSC) and carrying a singleton fetus between 12 weeks' and 28 weeks' gestation received daily 100 mg aspirin or placebo until 36 weeks' gestation or delivery and were monitored until 6 weeks' postpartum. The composite primary outcome comprised IUGR, perinatal mortality, or miscarriage. Analysis was done in the intention-to-treat population. The trial was registered in the Pan African Clinical Trial Registry (PACTR202001787519553) and ClinicalTrials.gov (NCT05253781). FINDINGS: Between July 1, 2020, and May 27, 2024, 619 pregnant women with HbSS and HbSC were screened, of whom 476 eligible women were recruited; 239 received aspirin 100 mg from a median gestational age of 19·0 (16·0-24·0) weeks and 237 received placebo from a median gestational age of 20·5 (15·5-25·0) weeks. 41 withdrew, died, or were lost to follow-up before 36 weeks' gestation. There was no significant difference in the risk of the primary endpoint: 59 (27·1%) of 218 women in the aspirin group versus 54 (25·8%) of 209 women in the placebo group (risk ratio 1·05 95% CI 0·75-1·46). More sickle-cell crises occurred with aspirin than with placebo (mean frequency of 32·64 SD 71·17 per 100 women with aspirin versus 30·38 75·95 per 100 women with placebo, incidence rate ratio 1·04 95% CI 1·01-1·08). There were ten (4·2%) maternal deaths in the aspirin group versus two (0·1%) in the placebo group (risk ratio 4·96 95% CI 1·18-20·92). INTERPRETATION: Low-dose aspirin was not beneficial for preventing IUGR, perinatal mortality, or miscarriage in sickle cell pregnancy, although this conclusion is limited by late initiation of the medication after 16 weeks' gestation in three-quarters of the participants. Low-dose aspirin, however, increased sickle-related complications compared with placebo, thus studies to clarify its safety in pregnant women with sickle cell disease are required. FUNDING: Tertiary Education Trust Fund Nigeria.
Afolabi et al. (Mon,) studied this question.