To sleep or to breastfeed: Associations between feeding method and sleep in infants and children

This study aimed to understand the association between feeding method, specifically breastfeeding versus non-breastfeeding, at 6 and 12 months and infant sleep over the first 3 years of life.

A sample of 444 mother-infant dyads from the Maternal Adversity, Vulnerability and Neurodevelopment cohort were analysed. Based on retrospective maternal reports between 3-24 months, infants' breastfeeding status was determined at 6 and 12 months. Nocturnal sleep duration, longest period of consecutive sleep, and total sleep over 24 h were measured by maternal reports at 6, 12, 24 and 36 months.

Generalized Estimating Equations revealed no significant association between feeding status, both at 6 and 12 months, and nocturnal sleep duration or total sleep over 24 h between 6-36 months (p > 0.05). However, breastfeeding at both 6 and 12 months was associated with shorter periods of consecutive sleep, at 6 and 12 months (p < 0.05) but not at 24 and 36 months (p > 0.05).

Our findings suggest that breastfeeding seems to be associated with more infant sleep fragmentation but not with total sleep duration in early infancy. However, this sleep fragmentation does not persist into later infancy and early toddlerhood.