The Ontario Mother and Infant Study II examined changes in postpartum health outcomes, including breastfeeding initiation and discontinuation, for mothers and their infants and compared these results to data collected prior to the initiation of the Universal Hospital Stay and Postpartum Home Visiting Program policy change in 1998. Data were collected using cross-sectional surveys before discharge and at 4 weeks postdischarge. Ninety percent of the women surveyed at 4 weeks postpartum initiated breastfeeding. Of these, 84% were still breastfeeding at 4 weeks postpartum. None of the 3 major program components—extended length of stay, a postpartum phone call from a public health worker, or a postpartum in-home visit—were associated with breastfeeding continuation to 4 weeks. Discontinuation before 4 weeks postdischarge was associated with maternal attitudes toward breastfeeding, formula feeding or supplementation in hospital, infant readmission, and use of walk-in clinics for infant care.