This study assessed the trends in twin births and their survival in Bangladesh by analyzing over a quarter million live births during 1970-2018, pooled from all eight rounds of the Bangladesh Demographic and Health Survey. In these five decades, the twinning rate increased by 1.5 times, from 5.8 to 8.6 twins per 1000 maternities. The decadal twinning rates varied across maternal age, parity, body mass index, household wealth index, and geographic region. The gap in decadal neonatal, infant, and under-five cumulative survival probability between singleton and multiple births was found to be closing, using Kaplan-Meier curves. Child mortality decreased by 80% and 60% in singleton and multiple births respectively. However, the absolute size of child mortality in multiple births remained six times higher than in singletons and was concentrated in the neonatal period. The share of multiple births surged in all types of child mortality. We predict a further and faster rise in multiple births in the coming decades in the face of upward trends in maternal age overlapping with higher parities, education, career prospects, contraceptive use, and the future demand-supply of assisted reproductive technology. A particular focus on the improvement of perinatal and neonatal care with wider availability is warranted. Otherwise, increased multiple births might raise child mortality and create public health challenges.
Keywords: Bangladesh; Child mortality; Multiple births; Twinning rate; Twins.