Birth spacing, sibling rivalry and child mortality in India.

The detrimental impact of short preceding birth intervals on infant and early childhood mortality is well documented in demographic literature, although the pathways of influence within the relationship remain an area of debate. This paper examines the impact of the length of the preceding birth interval on under-two mortality in India, and examines the pathways through which short preceding birth intervals may lead to an increased risk of mortality. Three mortality periods are examined: neonatal, early post neonatal and late post-neonatal and toddler, using the 1992 Indian National Family Health Survey. A multilevel modelling approach is used to account for the hierarchical nature of the data. The determinants of infants following a short or long birth interval are also examined. The results show that short preceding birth intervals (< 18 months) are associated with an increased risk of mortality in all three age groups, and the effect is particularly marked in the early post-neonatal period. Significant interactions were found between the length of the preceding birth interval and maternal education, gender and the survival status of the previous child. The significance of these interactions varied with the age of the child. The results highlight the diluting effect that a higher level of maternal education has on the relationship between short preceding birth intervals and mortality risk. There is evidence to suggest that sibling rivalry is a pathway through which short birth intervals influence mortality, with the death of the previous sibling removing the competition for scarce resources, and resulting in lower risks of mortality than if the previous sibling was still alive. The greatest risks of an infant following a short birth interval are among those whose previous sibling died, high parities, those with young mothers, and those whose previous sibling was breastfed for a short duration.