Nearly 500 women participated in the one-month study, which found feeding at the breast was associated with a 4 percent reduction in the odds of ear infection.
After accounting for demographic and other related factors, researchers found that one month of feeding at the breast was associated with a 4 percent reduction in the odds of ear infection, and they found a 17 percent reduction in the odds for infants fed at the breast for six months of infancy Among infants who were fed only breast milk, either at the breast and/or pumped breast milk from a bottle, for the first six months, the odds of experiencing an ear infection increased by approximately 14 percent for infants fed pumped milk for 1 month and by 115 percent for infants fed with pumped milk for 6 months, according to the study.
“While it is not completely clear why ear infections may be related to bottle feeding, it could be because bottles can create a negative pressure during feeding,” said Sarah Keim, PhD, senior author of the study and principal investigator in the Center for Biobehavioral Health in The Research Institute at Nationwide Children’s, to Science Daily. “This negative pressure is then transferred from the bottle to the middle ear of the infant during feedings, which may precipitate ear infections.”
Ear infections, or otitis media, occur in about 83 percent of children in the US by age three, according to the NIH, but while common, can also lead to hearing loss in extreme cases.
“When otitis media occurs over and over again, damage to the eardrum, the bones of the ear, or even the hearing nerve can occur and cause a permanent, sensorineural hearing loss,” according to the American Speech-Language Hearing Association.
To learn about other factors indicating that a child is at risk for hearing loss, visit Hear the World Foundation.