Young Infant Mortality Associated with Preterm and Small-for-gestational-age Births in Rural Bangladesh: A prospective cohort study

Objective To assess the relative risk of mortality in preterm and small-for-gestational-age (SGA) infants during the first and second months of life in rural Bangladesh. Study design We analyzed data from a cohort of pregnant women and their babies in Sylhet, Bangladesh, assembled between 2011 and 2014. Community health workers visited enrolled babies up to 10 times from birth to age 59 days. Survival status was recorded at each visit. Gestational age was estimated from mother’s reported last menstrual period. Birth weights were measured within 72 hours of delivery. SGA was defined using the INTERGROWTH-21st standard. We estimated unadjusted and adjusted hazard ratios and corresponding 95% confidence intervals for preterm and SGA babies separately for the first and second month of life using bivariate and multivariable weighted Cox regression models. Results The analysis included 17,643 singleton live birth babies. Compared with term-AGA infants, in both unadjusted and adjusted analyses, preterm-SGA infants had the highest risk of death in the first (HR 13.25, 95% CI 8.65 - 20.31; AHR 12.05, 95% CI 7.82 - 18.57) and second month of life (HR 4.65; 95% CI 1.93 - 11.23; AHR 4.1, 95% CI 1.66 - 10.15), followed by preterm-AGA infants, and term-SGA. Conclusions The risk of mortality in preterm and/or SGA is increased for newborns and extends through the second month of life. Appropriate interventions to prevent and manage complications due to prematurity and SGA could improve survival during and beyond the neonatal period.