Trends in Inter-Birth Intervals in Developing Countries 1965-2014

Birth spacing patterns are a fundamental feature of any reproductive regime, with direct bearing on maternal and child health. Analyzing birth history data from 274 surveys (WFS, DHS, RHS, MICS) conducted in 66 countries from 1975 to 2014, we generate estimates of key parameters of inter-birth intervals for five-year historical periods 1965-69 to 2010-14. Estimates are generated for the second birth interval and for intervals of all orders pooled. The estimates provide convincing evidence, for all major regions, of substantial increase in the inter-birth interval during contemporary fertility transitions. As fertility falls from TFR = 6 to TFR = 2.5 the median interval lengthens, generally by more than 12 months. The increase is larger for the second interval than for all intervals, and in sub-Saharan Africa and Latin America and the Caribbean than in the other two major regions (South and Southeast Asia, and West Asia and North Africa). Correspondingly, the incidence of short intervals (