Breastfeeding and Child Behavior
by Anne Eglash MD, IBCLC, FABM
Several studies in the past have explored the relationship between breastfeeding and childhood behavior. The authors of this week’s study point out that results of previous research have shown mixed results, because they typically measured behavior at one point in time, such as at age 3 or age 5.
Today’s CQW article used parent-reported and teacher-reported behavior data from the Millennium Cohort Study, which follows the lives of 19,517 children across England, Scotland, Wales and Northern Ireland who were born in 2000-2001.
The authors explored whether breastfeeding duration affected child behavior at age 3, and whether the effect persisted through childhood and into adolescence. Breastfeeding data collected from the families at 9 months of age was categorized as never-breastfed, or breastfed less than 2 months, 2.0-3.9 months, 4-6 months, and greater than 6 months.
Parent-reported behavior was measured using the Strengths and Difficulties Questionnaire (SDQ) at ages 3,5,7,11, and 14 years, and teacher-reported behavior using the SDQ was collected at ages 7 and 11 years.
The researchers controlled for various confounders such as child’s sex, ethnicity, birth weight, gestational age, parental income, number of parents, siblings, maternal education, maternal mental health, etc.
The authors point out that this study oversampled families living in disadvantaged areas and ethnic minorities to make sure they were represented.
Results showed that, after controlling for the large number of confounders, children who had been breastfed had lower SDQ scores (less problematic behavior) than children who had not been breastfed. What else? Check the question.
- Teacher-reported behavior scores showed fewer behavioral difficulties at age 11 for children who were breastfed.
- Longer duration of breastfeeding was associated with improved parent-reported behavioral scores.
- All children, no matter the duration of breastfeeding, had more behavioral difficulties as they aged.
- There is no significant difference between breastfed vs non-breastfed children in parent-reported behavioral scores by age 14.
See the Answer
Shorter breastfeeding duration has been linked to a range of difficulties in children. However, evidence linking shorter breastfeeding duration to child behavioural problems has been inconclusive. Owing to an almost exclusive focus on early childhood in previous research, little is known about breastfeeding effects on behaviour throughout childhood and adolescence. This study examines the longitudinal effect of breast feeding on parent-reported behaviour in children aged 3–14.
Data come from the Millennium Cohort Study, a large, prospective, UK birth cohort study.
11,148 children, their parents and teachers.
This study maps the effect of breastfeeding duration on parent-reported child behaviour longitudinally, using latent growth curve modelling and on teacher-reported child behaviour using multiple regression analyses. Breastfeeding duration was assessed through parent interviews when the child was 9 months old. Children’s behavioural development was measured using parent-reported Strengths and Difficulties Questionnaires (SDQ) at 3, 5, 7, 11 and 14 years and teacher-reported SDQs at 7 and 11 years.
Breast feeding was associated with fewer parent-reported behavioural difficulties at all ages even after adjusting for potential confounders (<2 months: B=−0.22, 95% CI −0.39 to −0.04; 2–4 months: B=−0.53, 95% CI −0.75 to −0.32; 4–6 months: B=−1.07, 95% CI −1.33 to −0.81; >6 months: B=−1.24, 95% CI −1.44 to −1.04; B=adjusted mean difference of raw SDQ scores at age 3, reference: never breast fed).
This study provides further evidence supporting links between breastfeeding duration and children’s socioemotional behavioural development. Potential implications include intervention strategies encouraging breast feeding.
Although the parents of breastfed children reported less problematic behavior at age 11, the differences in the teacher-reported scores for breastfed vs not-breastfed were not as significant. But, of course, most parents will tell you that their children act very differently at home than they do at school.
Even by age 14, children who were breastfed had fewer behavioral difficulties, so the effect of breastfeeding persisted into adolescence.
The mechanism for these findings is unclear with more research needed, according to the researchers. The question is whether the difference in behavior is related to the bioactive properties of breastmilk, and/or breastmilk’s effect on infant metabolism, and/or the nurturing and attachment that occurs with direct breastfeeding.
By the way, earlier findings from this large data set have revealed that children who are breastfed are more likely to be healthier and show improved cognitive development.