There is considerable variation in the prevalence of breastfeeding, which allows for investigation of factors that influence the initiation and duration of breastfeeding and its association with well being of the mother infant dyad.

To better understand factors that influence (1) maternal breastfeeding status and (2) the “effects” of breastfeeding on mothers and infants.

Participants (n = 170) derive from a longitudinal Canadian study “Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN)”, a project designed to understand the pre- and postnatal influences on maternal health and child social-emotional development. Mothers provided data on breastfeeding status, early life adversity, oxytocin gene and oxytocin gene receptor polymorphisms, depression/anxiety, infant temperament and maternal sensitivity.

Early life adversity associated with a shorter breastfeeding duration and higher maternal depression levels. The relation between mothers’ early adversity and the duration of breastfeeding was mediated by mothers’ depression level, but only in women carrying one variant of the oxytocin rs2740210 gene marker (CC genotype). Mothers who breastfeed at 3 months acted more sensitively towards their infants when they were 6 months old and they in turn had infants who at 18 months showed reduced negative affectivity.

Women who have been exposed to early adversity are “living with the past” and they are, to certain extent, protected or more vulnerable to depression, depending on their genotype. Breastfeeding associated with higher maternal sensitivity, which associated with decreased negative emotionality in the infant at 18 months. Our results help to clarify associations between early life experiences, breastfeeding, and the mother-infant relationship.

The authors have not supplied their declaration of competing interest.