Growth & Development: The Growth of Very Low Birth Weight Infants

Infants born weighing less than 1500 grams are categorized as Very Low Birth Weight (VLBW). They tend to have many more medical problems, and a longer time before they are able to tolerate feeds and nursing at the breast. During this time the mother needs to express milk from the breast. In the developed world this tends to be done largely with an electric pump.

Manual expression has been very effective for many women and is used almost exclusively in the developing world. VLBW infants who were fed only their mother's preterm milk had decreased growth compared to intrauterine growth rates and infants fed formula. Human milk fortifier has been developed to help prevent this problem ( Schanler, 1995 ).

In a study of feeding strategies for infants born at 26 to 30 weeks gestation, preterm infants fed fortified human milk had slower weight and length gain than infants fed preterm formula. However the human milk fed infants had fewer illnesses and were discharged on average two weeks earlier than the infants fed preterm formula ( Schanler, 1999-1 ).

Fortification of Preterm Breastmilk

Early Feeding of VLBW Infants

1. These infants are almost exclusively fed by nasogastric (NG) tube early on.

2. They benefit by having skin-to-skin contact with the mother (Kangaroo care).

3. Mothers who use kangaroo care have been shown to breast feed longer and a greater percentage of them are nursing until one month after discharge ( Bier, 1996 and Whitelaw, 1988 ). Another study of a small number of infants showed that mothers having skin-to-skin contact were able to express more breast milk than mothers not having skin-to-skin contact with their babies ( Hurst, 1997 ). Pumping at the baby's bedside is also associated with increased breast milk production ( Meier, 2001 ).

4. Small VLBW infants who are not intubated may be put to the mother's breast after she has finished pumping. This allows the infant non-nutritive suckling and increases maternal breast stimulation. By 30 weeks gestation, many infants who are not intubated can coordinate sucking and swallowing at the breast when the breast has been partially emptied by pumping. Milk intake by the premature infant needs to be calculated by weighing with an electronic scale before and after feeding ( Meier, 2001 ).

5. When the baby is capable of bottle feeding they can be put to a full breast. Many infants have difficulty making the transition from bottle feeding to suckling at the breast ( Furman, 1998 ). Kliethermes and co-workers found that infants with in hospital NG supplementation in addition to breast feeding were more likely to be fully breast fed at hospital discharge and 3 months after discharge than those supplemented with bottles of pumped breast milk ( Kliethermes, 1999 ).

6. Mothers will need to express breast milk using a hospital grade electric pump until the baby is close to 40 weeks gestation. Starting milk expression before 6 hours after delivery and expressing milk at least 5 times/day is associated with continued breastfeeding beyond 40 weeks gestation ( Furman, 2002 ).

7. Pumping is not always easy and requires a commitment and dedication on the part of the mother. Mothers often report decreasing milk supply as the length of time they must pump increases. This may be related to stress. One study showed increased milk volume in mother's of preterm infants who listened to a relaxation audio tape compared to control mothers ( Feher, 1989 ).

8. Issues facing LBW infants apply also.

9. Human milk fortifier is added until infants go to breast.

10. Some VLBW infants with slow growth on breastmilk may have improved with ``high tech'' breastfeeding. This is a name given by mothers to the fractionation of breastmilk which creates a mostly hind milk that has higher lipid content and more calories ( Vasan, 1998 ).

11. Many physicians and nurses caring for the VLBW infant may fear that expression of breast milk may increase stress in these mothers. However mothers report that providing milk for their premature infant was their only connection to their sick newborn ( Meier, 2001 ).

12. Sisk and coworkers found that when mothers of VLBW infants in a NICU who had planned on feeding their infant formula received counseling on the benefits of breast milk to VLBW infants and received information on breast milk expression (pumping) for their infants, 85% of these mothers started breast milk expression. Measured levels of anxiety and stress were the same for mothers who had wanted to breastfeed initially and those who decided to express breast milk after the educational intervention ( Sisk, 2006 ).

Guidelines for the transition of the premature infant from the NICU to home, "NICU Graduate Going Home" have been developed by the physicians of the Academy of Breastfeeding Medicine ( ABM, 2004-2 ).