Study site and population The study will be conducted in the Ejisu-Juaben and Sekyere East districts of the Ashanti Region of Ghana. Enrolment will be done simultaneously at the antenatal clinics of the Effiduase and Juaben district hospitals and a sub district health centre in each of the districts. The Effiduase and Juaben hospitals have 50 and 40 beds respectively and provide all basic medical services including adult medicine, paediatrics, surgery and obstetrics and gynaecology. They run weekly antenatal clinic sessions and together they register an average of 220 new pregnant women per month. The sub district health centres (at Kwaso and Kumawu) are manned by qualified medical assistants and midwives. Together they register an average of 80 new pregnant women per month. All health facilities in the study districts including the proposed enrolling clinics offer SP-IPT to pregnant women following the MoH guidelines. Pregnant women in their second or third trimester diagnosed with malaria are treated with AQ+AS as recommended by the MoH at these facilities. The study population will comprise pregnant women presenting at the hospital's antenatal clinic with a gestation of 16 to 24 weeks at their first booking.