Heterogeneous Effects of Birth Spacing on Neonatal Mortality Risks in Bangladesh

Abstract

The negative relationship between birth interval length and neonatal mortality risks is well documented, but heterogeneity in this relationship has been largely ignored. Using the Bangladesh Maternal Mortality and Health Care Survey 2010, this study investigates how the effect of birth interval length on neonatal mortality risks varies by maternal age at birth and maternal education. There is significant variation in the effect of interval length on neonatal mortality along these dimensions. Young mothers and those with little education, both of which make up a large share of the Bangladeshi population, can disproportionately benefit from longer intervals. Because these results were obtained from within-family models, they are not due to unobservable heterogeneity between mothers. Targeting women with these characteristics may lead to significant improvements in neonatal mortality rates, but there are significant challenges in reaching them.

Figure 1

Marginal effect of birth interval length on risk of neonatal mortality, by maternal age at birth NOTE: Figures reflect the change in the probability of neonatal mortality associated with a one‐year increase in the length of the preceding inter‐birth interval. The left panel presents predictions under the assumption that there is no correlation between family‐specific unobserved heterogeneity and the length of the preceding interval. The right panel presents predictions after adjusting for maternal fixed effects. All other covariates held at their mean values.

Figure 2

Marginal effect of birth interval length on risk of neonatal mortality, by maternal age at birth and child's birth cohort NOTE: Figures reflect the change in the probability of neonatal mortality associated with a one‐year increase in the length of the preceding inter‐birth interval. The panels refer to births occurring within the specified years. All covariates held constant at their mean values. Estimates based on within‐family models.

Figure 3

Marginal effect of birth interval length on risk of neonatal mortality, by maternal education and age at birth NOTE: Figures reflect the change in the probability of neonatal mortality associated with a one‐year increase in the length of the preceding inter‐birth interval. The panels refer to births occurring within the specified years. All covariates held constant at their mean values. Estimates based on within‐family models stratified by maternal education.