Low-dose aspirin and anaemia risk in pregnancy: A scoping review with emphasis on low- and middle-income contexts

Background: Anaemia remains a major public health concern in pregnancy and is associated with adverse maternal and perinatal outcomes. Low-dose aspirin (LDA) is widely prescribed to reduce the risk of preeclampsia (PE), yet its effects on haemoglobin (Hb) levels and anaemia risk are poorly characterised.
Methods: This scoping review mapped available evidence on the association between LDA use and Hb concentration or anaemia outcomes in pregnant women. The review followed Joanna Briggs Institute methodology and was reported in accordance with PRISMA-ScR. PubMed, Google Scholar, Scopus, Web of Science and the Cochrane Library were searched from inception to December 2025. Eligible studies included pregnant women prescribed LDA, a comparator group and reported Hb- or anaemia-related outcomes, with particular focus on low- and middle-income country (LMIC) settings. Studies were screened, and data were extracted using a standardised charting tool by one reviewer and independently checked by a second reviewer. Evidence was analysed descriptively using a two-stage approach.
Results: Thirteen studies met the inclusion criteria, comprising one case report with a narrative review, four observational cohort studies, four systematic reviews, two randomised controlled trials (RCTs) and two secondary analyses of RCTs. Most studies evaluated LDA for PE prevention, while only two pregnancy-specific studies directly assessed Hb outcomes. Bleeding-related haematologic endpoints were variably reported, but no study evaluated anaemia incidence.
Conclusion: Evidence on the relationship between LDA use and anaemia in pregnancy remains limited and inconclusive. Available studies lack standardised haematologic endpoints, and LMIC-specific data are sparse.
Contribution: This review highlights critical evidence gaps and underscores the need for well-designed prospective studies incorporating standardised anaemia-related outcomes in pregnant populations, particularly in LMIC contexts.