Antenatal and perinatal predictors of infant mortality in rural Malawi

BACKGROUND The slow pace in the reduction of infant mortality in sub-Saharan Africa has partially been attributed to the epidemic of human immunodeficiency virus (HIV) infection. To facilitate early interventions, antenatal and perinatal predictors of 1st year mortality were identified in a rural community in southern Malawi. METHODS A cohort of 733 live born infants was studied prospectively from approximately 24 gestation weeks onwards. Univariate analysis was used to determine relative risks for infant mortality after selected antenatal and perinatal exposures. Multivariate modelling was used to control for potential confounders. FINDINGS The infant mortality rate was 136 deaths/1000 live births. Among singleton newborns, the strongest antenatal and perinatal predictors of mortality were birth between May and July, maternal primiparity, birth before 38th gestation week, and maternal HIV infection. Theoretically, exposure to these variables accounted for 22%, 22%, 17%, and 15% of the population attributable risk for infant mortality, respectively. INTERPRETATION The HIV epidemic was an important but not the main determinant of infant mortality. Interventions targetting the offspring of primiparous women or infants born between May and July or prevention of prematurity would all have considerable impact on infant survival.