The Milk, Growth and Microbiota Study
The Milk, Growth and Microbiota Study
Late preterm infants, who are born at 34, 35 or 36 weeks gestation, often have difficulty
 feeding, establishing growth, and fighting off infection. Breastfeeding provides improved
 nutrition to help fight infection, in part because breast milk encourages the growth of
 healthy bacteria (microbiota) in the infant's intestine. However, when mothers give birth
 preterm, their breasts are usually not quite ready to make milk; it can take several days to
 have enough breast milk to match a baby's nutritional needs. If there is not yet enough
 breast milk, formula is often used. However, formula can interfere with the growth of healthy
 intestinal bacteria. An alternate nutritional option is donor milk from a certified milk
 bank, which is available in all neonatal intensive care units (NICUs) in San Francisco.
 However, no scientific studies have yet studied donor milk for late preterm infants, so
 currently all San Francisco NICUs (as well as the large majority of NICUs nationwide) reserve
 donor milk for infants born at <34 weeks. This study's investigators therefore propose the
 "Milk, Growth and Microbiota (MGM) Study," a randomized controlled trial to compare banked
 donor milk to formula for breastfeeding late preterm infants born in San Francisco. Once
 enrolled in MGM, infants will be randomly assigned to receive either formula or banked donor
 milk if they need additional nutrition until their mothers are making enough milk. After
 enrolling the babies, investigators will weigh them daily to assess their growth. The
 investigators will also collect infant bowel movements at baseline, 1 week and 1 month to
 determine whether donor milk vs. formula impacts the type of bacteria in the baby's
 intestine. If the study's results show that donor milk optimizes growth while helping
 establish healthy bacteria in the baby's intestine, donor milk might be postnatal strategy to
 bolster neonatal nutrition for late preterm infants.
In the U.S., 8% of all births occur between 34 0/7 and 36 6/7 weeks gestation and are
 regarded as late preterm birth. Compared to term newborns, late preterm newborns have a much
 higher risk of morbidity and mortality, in part because of difficulty establishing feeding
 and growth. Breastfeeding optimizes the nutrition of these infants by supporting growth and
 establishing a healthy intestinal microbiota. However, maternal breast milk production is
 often delayed after preterm birth, which can hamper optimal growth. When this occurs,
 clinicians may use formula to supplement breastfeeding. However, formula alters neonatal
 intestinal microbiota and can impede some of the benefits of a human milk diet. Donor milk
 from a certified milk bank could possibly be used instead of formula for supplementation
 prior to the onset of copious maternal milk production. However, the use of banked donor milk
 has never been studied in late preterm infants. The aim of this proposal is to report the
 effects of banked donor milk vs. formula on growth and on intestinal microbiota among late
 preterm, breastfeeding newborns who require additional nutrition before copious maternal milk
 is available. This study's investigators therefore propose a randomized, controlled trial
 enrolling late preterm newborns. Newborns will be randomly assigned either to breastfeed with
 additional formula feedings, or to breastfeed with additional donor milk feedings. The
 study's outcomes will be: (1) growth (rate of weight change), and (2) intestinal microbiota.
 If the study finds that temporary use of donor milk supports growth and maintains healthy
 intestinal microbiota until copious maternal milk becomes available, temporary use of donor
 milk might be a postnatal strategy to bolster neonatal nutrition and optimize nutritional
 support and growth for late preterm infants.
Inclusion Criteria:

 -  Late preterm newborns >=34 weeks and <37 weeks gestation

 -  Breastfeeding

 -  Clinical team plans to start supplementation

 Exclusion Criteria:

 -  Mothers are producing copious breast milk

 -  Birth weight <2100gm

 -  Any maternal or infant contraindication to breastfeeding