Child growth during weaning depends on whether mother is pregnant again.

Few longitudinal studies are available which relate data on breastfeeding and growth of the last-born child to data on the mother's subsequent pregnancy. The purpose of the present prospective study from Bhutan was to compare growth rate of children weaned during a subsequent pregnancy, with those of children weaned at the same age, but from non-pregnant mothers. Measurements of weight of 113 children and interviews with their mothers were done monthly through 32 months during the children's first 3 years of life. The period of overlap between lactation and pregnancy had a median duration of 5 months, and increased with an average of one week for each month reduction in the subsequent birth interval (P< 0.01). Children who stopped breastfeeding during their mothers' subsequent pregnancy showed a reduced growth rate during the last months before termination of breastfeeding when compared to children weaned at the same age, but from non-pregnant mothers (P = 0.04), and when compared to children who continued breastfeeding (P = 0.06).