Effects of Malaria Interventions During Pregnancy on Low Birth Weight in Malawi

Introduction: In malaria-endemic countries, malaria during pregnancy is associated with adverse birth outcomes, including low birth weight (i.e., <2.5 kg). However, the effects of the widely promoted and recommended approaches of intermittent preventive treatment for malaria in pregnancy and insecticide-treated nets for pregnant women on low birth weight have been insufficiently examined. This analysis investigates the independent and combined effects of intermittent preventive treatment for malaria in pregnancy and insecticide-treated nets on low birth weight among Malawian children. Methods: Using pooled data sets from 2004, 2010, and 2015–2016 Malawi Demographic and Health Surveys, a total of 18,285 births were analyzed between August and December 2019. Binomial generalized linear regression models with a log-link function explored the associations under consideration. Results: The overall low birth weight prevalence was 10.3%. Prevalence was lower in children whose mothers used adequate intermittent preventive treatment for malaria in pregnancy (adjusted prevalence ratio=0.88, 95% CI=0.79, 0.99) or used insecticide-treated nets (adjusted prevalence ratio=0.89, 95% CI=0.79, 0.99) than their respective counterparts. Low birth weight was 20.0% lower among children whose mothers adequately used both intermittent preventive treatment for malaria in pregnancy and insecticide-treated nets than those without these approaches (adjusted prevalence ratio=0.80, 95% CI=0.68, 0.93). Iron supplement consumption and survey year were significant effect modifiers on the relationship between intermittent preventive treatment for malaria in pregnancy and low birth weight. Conclusions: There were evident benefits of independent and combined use of intermittent preventive treatment for malaria in pregnancy and insecticide-treated nets on low birth weight, thereby supporting the use of these interventions during pregnancy. The reduced protective effects of intermittent preventive treatment for malaria in pregnancy over time highlight the need for innovative preventive methods against malaria in pregnancy.