Present or Absent: Risks and protective factors of sudden infant death syndrome (SIDS) in the Zambian context.

Background: Despite a reduction in Sudden Unexplained Infant Death (SUID) in high-income countries, the incidence of SUID and the prevalence of its risk and protective factors remain poorly understood in Zambia due to limited research. The aim of our study was to describe the infant sleep positions and sleep environments in an urban Zambian population to gain a better understanding of the modifiable risk factors for SUID. Methods: Data from the Zambian Infant Cohort Study (ZICS), a prospective birth cohort, were collected to describe infant sleep practices in Chawama, a densely populated peri-urban community in Lusaka, Zambia. During the 20-week study visit a structured questionnaire was administered to obtain data about the sleeping and environmental risks associated with SUID. Results: Data were collected from 596 caregivers and 605 infants. Only 6.4% of caregivers did attain an education beyond secondary school, and a significant proportion of infants (20.2%) had low birth weights, with 10.7% of infants confirmed by ultrasound as preterm. Furthermore, 96.5% of infants were placed to sleep on their side or in a prone position, and 98.2% of infants shared a sleep surface with their caregiver. Breastfeeding, a protective factor, was highly prevalent, with 90.2% of infants receiving some form of breastfeeding at the 24-week visit. Conclusion: The results of this study show that both modifiable (bed-sharing and prone sleep position) and non-modifiable risk factors (low birthweight and prematurity) of SUID are prevalent in this low socioeconomic setting in Zambia. Public health strategies to prevent SUID will need to be innovative and culturally congruent in addressing modifiable risks, such as bedsharing, in settings where there is a lack of space. Trial registration: Trial number: 1R01HD094650.