The aim of this study is to conduct a pilot randomized controlled trial of the effect of early limited formula supplementation on breastfeeding-related outcomes for infants with high early weight loss. The investigators will enroll 40 exclusively breastfeeding infants at 24-48 hours of age and will randomly assign them to early limited formula supplementation following nursing (intervention group) or to no formula feeding (control group). Both groups will receive intensive lactation support. Outcome variables will include breastfeeding status on day-of-life 8, weight nadir, breastfeeding self-efficacy, maternal satisfaction, and exclusive and partial breastfeeding at 1-3 months. The hypothesis for this study is that early limited formula supplementation might help infants with early weight loss avoid eventual weight loss ≥ 10% and associated breastfeeding problems.