Causes and risk factors for deaths in young infants in South Asia: the ANISA prospective population-based observational cohort study

Introduction Strategies for reducing infant mortality require accurate, local, population-level data. We conducted a population-based observational study in three countries in South Asia to describe risk factors, causes and rates of mortality in young infants. Methods Pregnancies, births and pregnancy outcomes were determined through household surveillance, and cause of deaths was ascertained by verbal autopsy. Cox regression was used to identify risk factors for deaths during days 0–<3, 3–<7 and 7–<60. Results Among 73 622 pregnancy outcomes, 4638 deaths were identified, including 1669 stillbirths (36.0%), 1347 (29.0%) deaths among non-registered liveborn infants who died before the first home visit by community health workers (CHWs), and 1622 (35.0%) deaths that occurred during days 0–<60 among liveborn registered infants. Most deaths among liveborn infants (59.3%, 1757 of 2965) took place within 3 days of birth. The most common causes of death over the young infant period were infections/sepsis (32.5%, n=963 of 2,965), birth asphyxia (29.0%, n=859) and preterm birth/low birth weight (14.1%, n=418). Risk factors for mortality included early morbidity (need for resuscitation, intrapartum infection/antibiotics, multiple gestation, congenital anomalies), environmental factors (smoke exposure, maternal betel chewing) and poor maternal access to quality care (history of a prior neonatal death, lack of care seeking for labour complications). Protective factors included biology (female sex, higher birth weight), essential newborn care (immediate breastfeeding, clean cord care) and access to quality maternal and newborn care (antenatal care, facility birth, skilled birth attendant, maternal education, household wealth). Conclusions Our population-based data highlight the importance of addressing deaths due to birth asphyxia and infections, while recognising that the relative burden of deaths due to preterm birth and congenital anomalies is increasing globally. Access to quality community-based and facility-based maternal and newborn care is critical to efforts to reduce mortality in young infants in high-mortality settings such as rural South Asia.