Relationship of newborn weight loss to milk supply concern and anxiety: the impact on breastfeeding duration.

Milk supply concern is the most common reason for breastfeeding discontinuation and maternal anxiety is also associated with reduced breastfeeding duration. Newborn excess weight loss (EWL) could trigger milk supply concern and anxiety and might be amenable to modification. Our objective was to determine the relationship between EWL and the development of milk supply concern and anxiety and the effect of such development on breastfeeding duration. We conducted a cohort analysis using data previously obtained from a randomised controlled trial comparing two post-hospital discharge follow-up strategies. For 1107 well, singleton infants born at ≥34 weeks, we extracted data on all inpatient infant weights. EWL was defined as the loss of ≥10% of birthweight. We surveyed mothers to obtain data on state anxiety and milk supply concern at birth and at 2 weeks. Our final outcome was breastfeeding at 6 months. Seventy (6.3%) infants developed EWL during the birth hospitalisation. At 2 weeks, milk supply concern and positive anxiety screen were more common (42% and 18%, respectively) among mothers whose infants had had EWL than among mothers whose infants had not had EWL (20% and 6%, respectively) (P < 0.001 for each comparison). Mothers with milk supply concern at 2 weeks were much less likely to be breastfeeding at 6 months, with odds ratio of 0.47 (0.30, 0.74) in multivariate analysis. EWL may increase milk supply concern and anxiety and these may reduce breastfeeding duration. Ameliorating EWL might alleviate milk supply concern and anxiety and improve breastfeeding duration.