Birth intervals

Abstract

Birth intervals (and closely related terms including birth spacing, interbirth interval, and interpregnancy interval) are of interest in biological anthropology and other population sciences because the timing and pace of childbearing both reflect and influence a range of demographic, biological, and social processes. Birth intervals vary greatly among human populations and this variation can be understood in terms of pathways linking behavior and environmental conditions to reproductive physiology. In noncontracepting populations, the most important proximate determinants of birth intervals operate through their influence on the fecundity‐suppressing effects of lactation and the waiting time to conception once postpartum fecundity has returned. Short birth intervals are associated with increased morbidity and mortality of fetuses and children on both ends of an interval, and with a variety of health risks for mothers.