Know the Flow: Milk Flow Rates From Bottle Nipples Used in the Hospital and After Discharge.

Background: Milk flow rate may play an important role in an infant's ability to safely and efficiently coordinate sucking, swallowing, and breathing during feeding.

Purpose: To test milk flow rates from bottle nipples used in the hospital and after discharge.

Methods: Bottle nipples used in hospitals (10 unique types) and available nationwide at major retailers (15 unique types) were identified. For each of the 25 nipple types, 15 nipples of that type were tested by measuring the amount of infant formula extracted in 1 minute by a breast pump. Mean milk flow rate (mL/min) and coefficient of variation (CV) were calculated for each nipple type. Comparisons between nipple types were made within brand and within category (eg, Slow, Standard). A cluster analysis was conducted to identify nipples of comparable flow.

Results: A total of 375 individual nipples were tested. Milk flow rates varied widely, from 0.86 to 37.61 mL/min. There was also a wide range of CVs, from 0.03 to 0.35. Packing information did not accurately reflect the flow rates of bottle nipples. The cluster analysis revealed 5 clusters of nipples, with flow rates from Extra Slow to Very Fast.

Implications For Practice: These data can be used to guide decisions regarding nipples to use for feeding infants with medical complexity in the hospital and after discharge.

Implications For Research: Research on infant feeding should consider the flow rate and variability of nipples used, as these factors may impact findings.