["As part of an assessment of breastfeeding and child health in Guinea-Bissau, we investigated the impact of mother's reason for weaning on subsequent child mortality.", 'Children were identified and followed by the demographic health surveillance system of the Bandim Health Project in Guinea-Bissau. Breastfeeding status and survival were ascertained by 3-monthly follow-up home visits. At termination of breastfeeding mothers were interviewed about her reasons for weaning. In all, 1423 children who terminated breastfeeding after 12 months of age were followed to 3 years of age.', "Median length of breastfeeding was 22 months. Following termination of breastfeeding, 66 children died before 36 months of age. In all, 62% (879/1423) were weaned because they were 'healthy'. Compared with the 'healthy' children, all other causes of weaning were associated with a higher mortality (mortality ratio [MR] = 2.97, 95% CI: 1.54-5.73). For 237 children weaned due to a new pregnancy the MR was 3.25 (95% CI: 1.45-7.30). Seventy-five children weaned because of illness had a 2.98 (95% CI: 0.95-9.39) fold excess mortality compared with children considered healthy. Excess deaths in the 'non-healthy' group accounted for 44% (29/66) of post-weaning deaths. Median length of spacing between an index child and a new sibling was 28 months irrespective of whether the index child survived or died before 3 years of age. The majority of the deaths occurred before birth of the new sibling."] Is termination of breastfeeding after 12 months of age due to a new pregnancy and other causes associated with increased mortality in Guinea-Bissau?