Associations between bottle-feeding intensity and maternal encouragement of bottle-emptying.

Objective: To explore longitudinal associations between bottle-feeding and maternal encouragement of infant bottle-emptying during the first 6 months of infancy.

Design: Mothers completed questionnaires during the third trimester of pregnancy, then monthly during the first 6 months postpartum. Questionnaires assessed family demographics, maternal and infant weight status, infant feeding patterns and maternal encouragement of infant bottle-emptying.

Setting: The Infant Feeding Practices Study 2, conducted by the US Centers for Disease Control and Prevention and the Food and Drug Administration.

Subjects: Mothers (n 1776).

Results: Repeated-measures regression was used to explore associations between bottle-feeding intensity (BFI; defined as the percentage of daily feedings that were from a bottle) and encouragement of bottle-emptying. Mothers who reported consistently high or consistently low BFI also exhibited consistently higher or lower frequency of encouraging their infants to empty the bottle (respectively) across the first 6 months of infancy, whereas mothers who reported increases in their BFI also exhibited concomitant increases in the frequency to which they encouraged their infants to finish the bottle. More frequent encouragement of bottle-emptying was also associated with feeding expressed breast milk (P<0·001), and lower parity (P=0·01), pre-pregnancy BMI (P=0·002) and infant birth weight (P=0·001).

Conclusions: More frequent use of bottles for infant feeding was significantly associated with more frequent encouragement of bottle-emptying. Further research using causal designs is needed to better understand whether the use of bottles promotes this controlling feeding practice or whether mothers with more controlling feeding practices opt to bottle-feed.