Exploring the Feasibility and Acceptability of Providing Caregivers Who Formula-feed with Smaller Infant Bottles in a Primary Care Clinic

Larger bottle size is associated with faster weight gain in infants, but little is known about acceptability and feasibility of providing bottles in primary care clinics.We randomized parent-infant dyads (N = 40) to receive a set of 4-ounce bottles or to continue using their own bottles. Demographic and anthropometric information were collected at enrollment and one follow-up visit 1-5 months later. The primary aim was to assess feasibility and acceptability of the intervention strategy. We compared components of bottle feeding, including usual bottle sizes used, number and volume of feeds with Wilcoxon rank-sum tests, and changes in weight-for-age and weight-for-length z-scores during the study period with t-tests, using p 0.05 as an indicator of statistical significance.Of participants randomized to receive bottles, 90% were using the 4oz bottles at follow up. The intervention group reported a significantly lower median bottle size (4oz) than the control group (8oz) at follow up, and parents reported acceptability and continued use of the bottles.An intervention to provide smaller bottles was feasible, mostly acceptable, resulted in lower median bottle size. Further research is needed to determine whether it represents a novel way to prevent rapid infant weight gain.