Relationship between intention to supplement with infant formula and breastfeeding duration.

OBJECTIVES According to Health Canada and the Canadian Paediatric Society, infants should be exclusively breastfed for the first six months with continued breastfeeding for two years and beyond. This study examined the relationship between a mother's intention to supplement with infant formula and the risk of discontinuing breastfeeding during the 12 months postpartum. METHODS Surveys were administered to a cohort of mothers at 6 weeks, 6 months and 12 months postpartum as part of York Region's Infant Feeding Survey. Those who initiated breastfeeding were included in the analysis (n=345). The relationship between a mother's prenatal intention to supplement with infant formula and breastfeeding duration was examined using Cox proportional hazards regression controlling for mother's age, prenatal education, immigration status, parity, household income, mother's ethnicity and education. RESULTS Nearly one third of mothers intended to supplement with infant formula. Of those mothers, 69% actually supplemented their baby with infant formula within 12 months postpartum. Intention to supplement was found to be associated with shorter breastfeeding duration (HR=2.64, 95% CI 1.83-3.81). First-time mothers experienced shorter breastfeeding duration compared to experienced mothers (HR=2.13, 95% CI 1.39-3.27). Mothers who identified as European experienced shorter breastfeeding duration compared to East, Southeast or South Asian mothers (HR=1.79, 95% CI 1.05-3.06). CONCLUSIONS Continued breastfeeding is not only beneficial for the infant, but it also has important benefits for the mother. The analysis indicates that a mother's prenatal intent to supplement may be associated with shorter breastfeeding duration. Further research is required to confirm these findings and to address the underlying assumptions and limitations.