Estimates of Preterm Infants' Breastfeeding Transfer Volumes Are Not Reliably Accurate.

Background: Adequate human milk nutrition is critical for infant growth and neurodevelopment; however, low milk transfer volumes are common when establishing preterm breastfeeding. Despite clinical assessments of milk transfer volumes at the breast being inaccurate, measurement of feed volume via test weighing is rarely carried out either routinely or in cases where infant weight gain is inadequate.

Purpose: To assess the accuracy of the Preterm Breastfeeding Assessment Tool (PBAT) in determining transfer volumes and examine factors associated with PBAT accuracy.

Methods: Pre/postfeed weights were performed using electronic scales and PBAT scores recorded for 1186 breastfeeds in 60 preterm infants born less than 33/40 and 33 to 39/40 postmenstrual age. Measured milk intake volumes were converted to percent prescribed feed volume and compared with PBAT estimates of milk transfer.

Results: The PBAT is accurate in identifying when no milk is transferred at the breast but not in estimating transfer of half or the full prescribed volume (accuracy 26% and 47%, respectively). Wide ranges of transfer volumes (11-75 mL) were observed within and between infants, and for 20% of breastfeeds, no milk was transferred. Preterm Breastfeeding Assessment Tool accuracy decreased with each 1-week increase in birth gestation (odds ratio = 0.82; 95% confidence interval, 0.71-0.94; P = .004).

Implications For Practice: When establishing breastfeeding, test weighing facilitates adequate nutrition by guiding appropriate complementary feeding. For mothers breastfeeding several times per day in preparation for discharge home, test weighing may offer a useful tool for developing maternal confidence in assessing milk transfer. Preterm Breastfeeding Assessment Tool is inaccurate in assessing preterm infants' milk transfer volumes when breastfeeding.

Implications For Research: While studies have typically focused on medically stable infants, test weighing offers a useful tool to examine breastfeeding efficacy and inform nutritional management of preterm infants with complications such as chronic lung and cardiac disease.