1.7 Rapid repeat births (probabilities and proportions)

In low- and middle-income countries, births that occur in quick succession carry exceptionally high excess mortality and morbidity risks to children. Rapid repeat births are defined variously in the literature but in this analysis it considers birth that occur less than 24 months after a previous birth (and before an adolescent’s twentieth birthday). The analysis will look at both the proportions and probabilities of rapid repeat births in adolescence. Both the proportions and probabilities have important differences. The proportion is valuable for lay audiences and policy-makers in that it is easy to understand—it measures the proportion of all non-first births that occurred in less than 24 months after a previous birth to adolescents mothers. In West Africa this proportion was exceptionally high. Between 40-50% of all non-first births to adolescents were rapid repeat births. However, the proportions do not account for the fact that many adolescent birth intervals are not closed by an additional birth before age 20. The probabilities correct for these open-ended intervals, and as such are important for better identifying whether the risk of rapid repeat births is changing for all adolescents, not just those adolescents who have multiple births in quick succession (which are identified in the proportions). The analysis will produce country-specific, regional and global trends.