Oropharyngeal Mother’s Milk for Extremely Low Birthweight Infants
by Anne Eglash MD, IBCLC, FABM
A fetus swallows approximately 200 ml/kg/day of amniotic fluid, which contains many immunoprotective qualities. For example, amniotic fluid contains immunoglobulins, cytokines, and intestinal growth factors. According to the authors of this week’s article, the fetal intestinal lining increases by more than 50% in the third trimester, and it is believed that the rapid intestinal development is due to the growth factors in amniotic fluid.
A full term infant is exposed to these growth and other immunologic factors until birth, and in an optimal situation, is put to the breast immediately, receiving continual oral and enteral (gut) exposure to immunoprotective and growth factors by breastfeeding.
Extremely low birth weight infants (ELBW, <1000 grams) often don’t receive oral feedings until approximately 32 weeks gestation. Prior to that they receive nasogastric or orogastric feedings, bypassing the mouth. This means that they have no oral exposure to bioactive factors in amniotic fluid or breastmilk for possibly as long as 10 weeks after birth.
This review highlights evidence that early oral exposure to mother’s milk, particularly colostrum, enhances intestinal development for ELBW infants, and appears to protect them from necrotizing enterocolitis (NEC). Not allowing the oral mucosa exposure to mother’s milk may increase the risk of NEC. This is a crucial issue for ELBW infants, since the risk of NEC is inversely associated with birth weight, meaning that ELBW infants are in the highest risk group for death from NEC.
NEC is caused by a variety of factors, including nonoptimal intestinal bacteria, injury to the lining of the gut, impaired immune defense, and an inappropriate proinflammatory state.
- Preterm colostrum has fewer bioactive factors than amniotic fluid.
- Fresh mother’s milk has a greater abundance of protective immunologic components than mother’s own milk that has been frozen, then thawed.
- For at least the first month postpartum, preterm milk has a higher concentration of factors that promote and protect the infant immune system as compared to milk from a mother with a term infant.
- Postbirth fasting of an ELBW infant has been associated with damage to the intestinal lining and an imbalance of gut bacteria.
- Intestinal growth factors from mother’s milk, when administered orally to an ELBW infant, can be absorbed thru the lining of the mouth, into the infant’s blood stream.
- ELBW infants who receive 0.2ml of mother’s own colostrum every 2-3 hours for 5 days have a lower risk of NEC during the NICU stay.
- ELBW infants need to receive regular oral exposure to mother’s own milk, starting from the first collection of colostrum until they transition to oral breastmilk feedings, in order to see a decrease in NEC rates.