Estimated Impact on Birth Weight of Scaling-up Intermittent Preventive Treatment for Malaria in Pregnancy Given Sulphadoxine-Pyrimethamine Resistance in Africa: a Mathematical Model

Background: Malaria transmission has declined substantially in the 21st century but pregnant women in areas of sustained transmission still require protection to prevent the adverse pregnancy and birth outcomes associated with malaria in pregnancy (MiP). A recent “Call to Action” has been issued to address the continuing low coverage of intermittent preventative treatment for malaria during pregnancy (IPTp). This call has, however, been questioned by some, in part due to concerns about resistance to sulphadoxine - pyrimethamine (SP) , the only drug currently recommended for IPTp. Methods and Findings: Using an existing mathematical model of MiPwe combined estimates of the changing endemicity of malaria across Africa with maps of SP resistance mutations and current coverage of antenatal access and IPTp - SP across Africa. Using est imates of the relationship between these mutations and the parasitological efficacy of SP during pregnancy , we estimate the varying impact of IPTp - SP across Africa and the incremental value of enhancing IPTp - SP uptake to match current antenatal clinic (ANC ) coverage. The risks of MiP and malaria - attributable low birthweight ( m LBW) in unprotected pregnan cies (i.e. those not using insecti ci de treated nets (ITNs)) leading to live births fell by 37% (33% - 41% 95% credible interval (crI ) ) and 31% (27% - 34 % 95% crI) respectively from 2000 to 2015 across endemic areas in sub - Saharan Africa . However , these gains are fragile , and coverage is far from optimal . I n 201 5 , 9.5 (8.3 - 10.4 05% crI) million (m) of 30.6m pregnancies in these areas would still have been infected with P. falciparum without intervention , leading to 750,000 ( 39 0 ,000 - 1 . 1 m 95% crI ) ) malaria - attributable LBW deliveries. 6.6 ( 5.6 - 7.3 95% crI) m of these 9.5m (69.3%) pregnancies at risk of infection ( and 53.4% [ 16.3 m /30.6m] of all pregnancies) occurred in settings with near - perfect SP curative efficacy (>99%) based on the most recent estimates of resistance . 4 4 % of these ...