Effect of Antenatal Monthly Sulfadoxine–Pyrimethamine, Alone or with Azithromycin, on Gestational Weight Gain and Anemia during Pregnancy and One Month Postpartum in Malawi: A Randomized Controlled Trial Secondary Analysis

Low gestational weight gain (GWG) and prenatal anemia are associated with adverse pregnancy, maternal and infant health outcomes. In a secondary analysis of a single-center, randomized, partially placebo-controlled, outcome assessor-blinded, controlled trial conducted in Malawi from 2003 to 2006, when antiretroviral treatment (ART) for HIV was not widely available, we studied whether GWG can be increased and the prevalence of maternal anemia decreased during pregnancy and at 1 month postpartum through the intermittent preventive treatment in pregnancy (IPTp) of maternal malaria and reproductive tract infections. The participants (≥15-year-old women with uncomplicated second trimester single pregnancies) received either sulfadoxine (1,500 mg) and pyrimethamine (75 mg; SP) twice (control group, n = 433), monthly SP (n = 439), or monthly SP and azithromycin (1,000 mg) twice (AZI-SP, n = 441) during pregnancy. The mean weekly GWG in the sample was 256 g/week. The participants in the monthly SP group gained, on average (95% CI), 4 g (-13 to 20; P = 0.671), and those in the AZI-SP group gained 25 g (8-41; P = 0.003) more weight per week than control group participants. Among HIV-positive participants (12%), the differences were larger and also significant between the monthly SP group and control group. Mean hemoglobin and anemia prevalence did not differ between the groups during pregnancy or postnatally. The data support a hypothesis that IPTp with monthly SP and two doses of azithromycin can increase GWG, especially among HIV-positive women who are not on ART, possibly through the reduction of infections, inflammation, and effects on the maternal gut microbiome.