Breastfeeding and behavioral problems in five-year-old Japanese children: The Kyushu Okinawa Maternal and Child Health Study

Abstract

PurposeThis prebirth cohort study examined the relationship between breastfeeding duration and behavioral problems in five-year-old Japanese children. MethodsStudy subjects were 1198 mother–child pairs. Data were collected using a self-administered questionnaire. Emotional, conduct, hyperactivity, and peer problems and low prosocial behavior were assessed using the Strengths and Difficulties Questionnaire (SDQ). ResultsNeither exclusive breastfeeding duration nor breastfeeding duration regardless of exclusivity was significantly associated with childhood emotional, conduct, hyperactivity, or peer problems or low prosocial behavior. In children with older siblings only, ≥ 4 months of exclusive breastfeeding was significantly inversely associated with hyperactivity problems (adjusted odds ratio [OR] = 0.57, 95 % confidence interval [CI]: 0.31−0.99). In children without older siblings, ≥ 4 months of exclusive breastfeeding was inversely significantly associated with low prosocial behavior (adjusted OR = 0.54, 95 % CI: 0.30−0.93). No interactions were observed between exclusive breastfeeding duration and the presence of older siblings regarding the two outcomes. ConclusionsNo associations were found between breastfeeding duration and any of the outcomes based on the SDQ. Exclusive breastfeeding for ≥ 4 months may be inversely associated with hyperactivity problems in children with older siblings and with low prosocial behavior in children without older siblings.