When discussing breast-feeding and the use of human milk (HM) both within the NICU and postdischarge, mothers, neonatologists, and primary care providers are all concerned with whether or not exclusive HM feedings (eg, without additional formula or formula powder supplements) support adequate infant growth. In order to answer that question, we must know (1) Is the infant getting enough milk during breast-feeding? (2) Does mom have the tools to facilitate adequate milk intake by the infant during breast-feeding? (3) How long does mom need to continue breast pumping? (4) Does exclusive HM actually provide adequate nutrition for preterm and high-risk infants?
I. Patterns of development
While the infantile suck reflex develops quite early during gestation, suction pressures in the infant, which are essential for effective latch onto the breast and milk transfer, continue to mature through 40 to 44 weeks' postmenstrual age (PMA).
For the preterm infant, slipping off the nipple repeatedly during a feeding is common because infants are unable to sustain the suction pressures required (approximately −50 mm Hg) to maintain an effective latch position at the breast.
Even stronger suction pressures are used to transfer milk from the breast to the infant during breast-feeding.
Sleep-wake-feeding regulation is immature in preterm infants first learning to breast-feed, so most demonstrate erratic waking, falling asleep early in the feeding, and appearing satiated after consuming only a few milliliters of milk.
Cues of satiety that are useful for healthy breast-fed infants do not apply indiscriminately to preterm infants.
Intake is expected to be minimal when infants first start feedings at the breast, but increases with infant maturity, maternal comfort with positioning, and learned timing of breast-feedings, so they begin immediately after the infant awakens.
Box 12-1 shows a sample feeding management strategy for a preterm infant who is transitioning to oral feedings during the late NICU hospitalization.
Getting enough milk at the breast is not a matter of learning and practice, but rather one of maturity on the part of the infant.
Standardized “one-size-fits-all” guidelines to manage inadequate intake during breast-feeding are not evidence based because some preterm infants demonstrate mature suction pressures at 34 weeks, whereas others reach 44 weeks before these pressures become effective with respect to milk removal at the breast.
Box 12–1 Transitioning to Cue-Based Breast-Feedings in the Late NICU Hospitalization