RESUMO
BACKGROUND: Randomized controlled trials in Guinea-Bissau and Uganda have revealed that the intensive promotion of exclusive breastfeeding (EBF) impairs growth in early infancy. When newborn growth is impaired, small amounts of formula may be combined with breastfeeding to promote growth. METHODS: To determine if breastfeeding combined with once-daily formula supplementation improves growth among at-risk newborns, we conducted a pilot randomized controlled trial in Bissau, Guinea-Bissau and Kampala, Uganda. We randomly assigned 324 healthy breastfeeding newborns who weighed 2000 g to 2499 g at birth or <2600 g at 4 days old to once-daily formula feeding through 30 days as a supplement to frequent breastfeeding followed by EBF from 31 days through 6 months, or to EBF through 6 months. The primary outcome was weight-for-age z score (WAZ) at 30 days. Other outcomes included weight-for-length z score (WLZ), length-for-age z score (LAZ), breastfeeding cessation, adverse events, and serious adverse events through 180 days. RESULTS: Daily formula consumption in the intervention group was 31.9 ± 11.8 mL. The random assignment did not impact WAZ, WLZ, LAZ, breastfeeding cessation, adverse events, or serious adverse events through 180 days. In the intervention and control groups, 19 (12%) and 35 (21%) infants, respectively, reported nonformula supplementation in the first 30 days (P = .02). CONCLUSIONS: Once-daily formula supplementation for 30 days was well-tolerated, but the small volume consumed did not alter growth through 180 days of age. Further research would be required to determine if larger formula volumes, longer duration of treatment, or more frequent feeding are effective at increasing growth for this at-risk population.