Presented at the Academy of Breastfeeding Medicine International Conferece, November 2018
Alison Stuebe, Roger Mills-Koonce, Samantha Meltzer‐Brody, Brenda Pearson, Karen Grewen
Background: Maternal-infant bonding is a commonly-cited benefit of breastfeeding.
Objective: We sought to quantify associations between breastfeeding intensity and attachment security at 12 months.
Methods:
We analyzed mother-infant pairs in an ongoing longitudinal cohort study. Women intending to breastfeed were recruited in the 3rd trimester of pregnancy for an ongoing longitudinal study. Psychiatric history was assessed via Structured Clinical Interview, with oversampling of women with a history or current diagnosis of major depressive disorder or anxiety disorders. Infant feeding was assessed monthly, with a 7-day recall of feeding at breast, expressed milk, or breastmilk substitutes. Breastfeeding intensity was calculated as the proportion of milk feedings that were at breast at each assessment. Attachment security was assessed at 12 months using the Ainsworth Strange Situation Paradigm (SSP). We used repeated measures analysis to quantify the extent to which at-breast feeding intensity was associated with attachment. Because infant sex has been reported to modify the effects of maternal behavior on socio-emotional development, we further stratified by infant sex.
Results:
Among 96 mother-infant pairs for whom SSP coding had been completed, 12/45 boys (26.7%) and 17/51 girls (33.3%) were insecurely attached. When we analyzed boys and girls together, we found no association between at-breast feeding intensity and secure attachment (p=0.50). However, the association differed by infant sex (p for interaction =0.03). Higher breastfeeding intensity was associated with secure attachment among girls (p= 0.01). Among boys, breastfeeding intensity was not associated with secure attachment (p=0.21).
Conclusions:
In an ongoing longitudinal cohort study, we found that the association between at-breast feeding intensity and secure attachment varied by infant sex. These findings suggest that stratified analyses by infant sex should be considered in studies of breastfeeding and socioemotional development.