The burden of malaria-attributable maternal anaemia and the impact of preventive treatment across sub-Saharan Africa

Malaria in pregnancy is a major but poorly quantified contributor to maternal anaemia in sub-Saharan Africa. We combined individual-level data on haemoglobin (Hb), gravidity, gestational age and PCR-confirmed Plasmodium falciparum infection from 12,608 pregnancies in 7 African countries with a gravidity-specific model of malaria exposure and immunity linked to contemporary maps of transmission and fertility. For 2023, we estimate that 13.1 million pregnancies in malaria-endemic African regions were exposed to P. falciparum . In the absence of preventive measures, this exposure would have resulted in 2.41 million (95% credible interval 1.98–3.04 million) cases of moderate or severe anaemia (Hb < 9 g dl ⁻¹ ), including 600,000 (408,000–906,000) severe cases (Hb < 7 g dl ⁻¹ ). A counterfactual scenario using 2,000 transmission levels suggests that a 32% reduction in exposure during pregnancy translated into only a 22% decline in intrinsic anaemia burden, reflecting a shift from a concentration of risk in primigravidae to a more even distribution across gravidities as multigravid women acquire less pregnancy-specific immunity. Calibrating our model to randomized trials, we estimate that under current coverage, intermittent preventive treatment of malaria in pregnancy using sulfadoxine-pyrimethamine averted around 1.10 million (0.72–1.61 million) cases of moderate or severe anaemia and 330,000 (225,000–523,000) severe cases in 2023. These findings show that although burden has declined substantially, malaria remains a major driver of maternal anaemia risk. Meanwhile, lower immunity across multigravidae means any interruption to intermittent preventive treatment of malaria in pregnancy using sulfadoxine-pyrimethamine, or other population-based malaria control efforts, risks rapid resurgence of severe maternal anaemia, with substantial consequences for maternal and neonatal health.