By Lisa Rapaport

(Reuters Health) – A growing number of extremely tiny newborns are being sent home from the hospital with human milk for feedings when their mothers don’t produce enough milk to meet their nutritional needs, a U.S. study suggests.

Preemies who consume breast milk may be less likely to develop infections or neurological problems than infants who don’t, previous research suggests. But mothers who deliver early may be unable to breastfeed right away if their milk hasn’t come in yet and they may also have a low milk supply because preemies are often unable to latch on to the breast and nurse efficiently to stimulate milk production.

For the current study, researchers examined data on 346,248 mothers and their very low birthweight preemies born at 802 hospitals nationwide from 2008 to 2017. Over the decade, the proportion of tiny preemies discharged with human milk to drink increased from 44% to 52%

“While human milk use has improved in the last decade among very low birthweight infants infants, there are considerable disparities by U.S. region and race/ethnicity that need to be addressed,” said Dr. Margaret Parker, lead author of the study and a researcher at Boston Medical Center and Boston University School of Medicine.

Pregnancy normally lasts about 40 weeks, and babies born after 37 weeks are considered full-term. In the weeks immediately after birth, preemies often have difficulty breathing and digesting food. Some premature infants also encounter longer-term challenges such as impaired vision, hearing and cognitive skills as well as social and behavioral problems.

Pediatricians recommend that mothers exclusively breastfeed infants until they’re at least 6 months old because it can bolster babies’ immune systems and reduce their risk of ear and respiratory infections, sudden infant death syndrome, allergies, obesity and diabetes.

The American Academy of Pediatrics recommends pasteurized human donor milk when mother’s milk is not available.

“Currently, the vast majority of hospitals that care for very low birth weight infants offer donor milk for this purpose,” Parker said by email. “If a hospital does not offer it, mothers can ask their hospital providers to obtain it

In the study, all of the babies were born weighing no more than 1,500 grams (about 3.3 pounds), at just 22 to 29 weeks’ gestation.

Human milk provision was higher in western and northeastern states than elsewhere in the country. It was also more common with multiple births, researchers report in JAMA Pediatrics.

Asian mothers got human milk at discharge more often than white women, while this happened less often among black, Hispanic, and Native American mothers.

The study wasn’t a controlled experiment designed to prove whether or how factors like race or ethnicity might directly impact whether women received human milk at hospital discharge.

One limitation of the study is that researchers only looked at human milk use at a single point in time, and they didn’t have data on how many mothers continued to use human milk for the first several weeks after they went home.

Ideally, mothers of preemies should start expressing milk with a breast pump within a few hours of birth and do this as often as possible to stimulate supply while preemies are too tiny and weak to nurse effectively, Parker advised. Mothers should also visit babies as often as possible, nurse when they can, and do skin to skin contact with infants.

“This is hard work and supportive family and friends can make a big difference,” Parker said. “Low milk supply is common among mothers of very low birth weight infants.”

SOURCE: JAMA Pediatrics, online September 3, 2019.