Child survival and intervals between pregnancies in Guayaquil, Ecuador

Summary Intervals between births to 1934 women from poor areas of Guayaquil, Ecuador, were subjected to analysis to determine what effect on survival chances of their children, if any, was exerted by differences in these intervals. The analysis showed that risks of miscarriage and stillbirth were increased when the interval between last termination of pregnancy and conception was either very short or very long. Post-neo-natal mortality was strongly influenced by the length of the interval, reaching a minimum where the interval was around three years. The influence of interval length diminished as the level of mortality fell (with improving health standards over time). The possibility could not be discarded that for neo-natal mortality and mortality in the second year of life, extremely short intervals (under three months) carried significant additional risks. For both periods, intervals longer than three years increased the risk of infant mortality. Evidence was found that the survival chances of the first child of a pair were seriously impaired during the first year of life where a fresh conception supervened during that period (the earlier this happened the more serious the impairment). An analysis of'double intervals' (not presented here) showed that the effects of short intervals were exaggerated when two such intervals succeeded one another. The principle conclusions remained valid when competing sources of association between short intervals and mortality were excluded, thus lending plausibility to the view that the two are connected by a causal chain. While no great precision can be claimed, it seems likely that if effective measures were taken to prevent the occurrence of pregnancy intervals shorter than 27 months (corresponding to birth intervals of less than three years) spontaneous abortions might be reduced by one-third and infant mortality by one-half in populations similar to that studied here. These results justify a recommendation that the prescription of contraception for a limited period post-partum in areas of moderate or high neo-natal mortality should become a routine of responsible obstetric or maternity and child welfare care.