Infant and fetal mortality among a high fertility and mortality population in the Bolivian Amazon

► Infancy in indigenous societies is often marked by high morbidity and stunted growth, despite socioeconomic change. ► Study incorporates detailed demographic interviews and ethnography among Tsimane Amerindians. ► Infant death is greater among young, monolingual Tsimane mothers with short interbirth intervals. ► Infant stunting is predicted by small maternal body size, high birth order, and early weaning. ► Contrary to widely documented patterns, maternal education among Tsimane does not associate with lower infant mortality.