Breastfeeding Tied to Reduced Risk of Serious Infant Infections

By Lisa Rapaport

October 26, 2020

(Reuters Health) - Longer duration of breastfeeding, as well as exclusive breastfeeding, are associated with lower risk of infant infections requiring hospitalization, a Danish study suggests.

Researchers examined data on 805 mother-infant pairs, using weekly text messages to collect data on breastfeeding until infants were weaned, and to collect data on any symptoms of infection biweekly from age 12 to 36 months.

A total of 777 mothers (95.3%) initiated breastfeeding, and the median duration of breastfeeding was 7.6 months. Overall, 626 infants (76.8%) were breastfed exclusively, with a median duration of 2.1 months; by 6 months of age, nine babies (1%) were exclusively breastfed.

There were 207 infants (25.4%) hospitalized one or more times during the study period due to infections, with a mean incidence rate of 14.63 per 100 person-years. Overall, researchers found no statistically significant difference between infection rates for infants who were never breastfed at all and those who were.

The duration of breastfeeding did make a difference, however. Each extra month of breastfeeding was associated with a lower risk of hospitalizations for infection (adjusted incidence rate ratio 0.96).

"The results support the importance of breast-feeding and mothers should be encouraged to breast-feed," said senior study author Dr. Steffen Husby, a professor of pediatrics at Hans Christian Andersen Children's Hospital at Odense University Hospital in Denmark.

Clinicians should still reassure mothers who formula feed that this isn't harmful, Dr. Husby said by email.

"This is a statistical effect and babies who are formula fed may cope very well with even serious infections in this environment," Dr. Husby said.

When researchers stratified infants by age, they found an association between duration of any breastfeeding and lower infection risk for babies up to 11 months (aIRR 0.96) but no connection at ages 12 to 36 months.

The duration of exclusive breastfeeding was associated with lower hospitalization rates for infection over the first 24 to 36 months of life (aIRR 0.88).

Infants who were exclusively breastfed for 4 months or more had a lower risk of hospitalizations for infections over the first 24 to 36 months of life (aIRR 0.45) compared to babies who were never breastfeed or not exclusively breastfed.

Researchers also looked at symptoms of infants who had infections at home but didn't receive hospital care. For these less serious infections, there was no association between the duration of any breastfeeding and the prevalence of any infection symptoms.

One limitation of the study is that the participants tended to be better educated and older than women in the general population of Denmark, limiting generalizability, the authors note in Pediatrics. It's also possible that in some instances, infections may have led mothers to stop breastfeeding.

Clinicians should support mothers in breastfeeding exclusively for six months and continuing for at least a year, said Dr. Lori Feldman-Winter, a professor of pediatrics at Cooper Medical School of Rowan University in Camden, New Jersey, and chair of the American Academy of Pediatrics Section on Breastfeeding.

"For infants whose mothers cannot breastfeed or do not breastfeed according to AAP recommendations, it is important to recognize the vulnerability that these infants face in terms of potentially harmful infections," Dr. Feldman-Winter, who wasn't involved in the study, said by email.

Clinicians should also promote infection prevention, Dr. Feldman-Winter added.

"Similar to advice we are giving to prevent the spread of COVID, it is important that those who care for infants be vigilant about hand washing, staying away from infants if they feel sick, and wear masks," Dr. Feldman-Winter said.

SOURCE: Pediatrics, online October 23, 2020.