Post-discharge Nutrition
Evidence suggests that during the Neonatal Intensive Care Unit (NICU) stay, infants who experienced slowest growth velocity had the highest incidence of morbidities (proven necrotising enterocolitis, late-onset infection,
bronchopulmonary dysplasia, and postnatal steroid therapy) that affect the provision and use of nutritional support and growth potential⁵.
An observational study has shown an association between poor neurodevelopmental outcome and slow growth from discharge to 8 months of age, irrespective of growth from birth to term⁶.

Breastfeeding post-discharge
For breastfed infants, a crucial factor may be achieving successful lactation by the mother before the infant is discharged from the NICU. One of the ways is to get the mothers to room-in and assist them in achieving successful lactation. If faltering growth occurs in breastfed infants, supplementation of maternal expressed
breastmilk with breastmilk fortifiers (like Cow & Gate Nutriprem breastmilk fortifier) may be advocated. Preterm infants fed unfortified human milk after discharge have growth rates and bone mass that are lower than formula-fed infants during infancy.

Indicators of successful breastfeeding are:
• Baby is awake and stays awake
• Latches on to the breast and stays on creating suction
• Suckles vigorously
• Demonstrates swallowing that can be heard
• The baby lets go of the breast by himself or herself
• The baby is relaxed and content after a feed

There is some evidence to suggest that additional phosphate is needed to help growth and bone mineralisation in the immediate post-discharge period if serum phosphate levels are <1.5 mmols/L. Infants who are exclusively breastfeeding should have vitamin D supplement as their needs will exceed the low levels supplied through breastmilk. It may be useful to continue vitamin D 200-400 IU/day. It is also recommended that breastfed infants should continue on iron post-discharge when on exclusive breastmilk. When breastmilk is replaced with formula milk, vitamin D supplements may be stopped. Infant formula should continue to 12-18 months’ corrected age depending on the adequacy of weaning diet.


Formula-fed post-discharge
Heterogeneous studies comparing the benefits of term, preterm formula and breastmilk have so far been inconclusive⁷. Nutritionally enriched preterm formulae (NEPF) are designed with the micronutrient needs of preterm infant in mind for whom additional calcium, phosphorus, zinc and iron may be an advantage. Calcium and phosphorus improve bone health, and zinc is needed to make up for early losses in gut secretions coupled with high requirements during infancy⁸. Formula-fed infants who are growth-restricted at discharge should have a NEPF (like Cow & Gate Nutriprem 2) continued until 3 months corrected age or until weaning is established. Formula-fed infants who are not growth-restricted at discharge would benefit from a NEPF until approximately 1 month corrected age. After discontinuing the NEPF, an iron supplemented term formula may be advisable until 12-18 months corrected age, depending on the adequacy of weaning diet⁹.

Factors affecting growth
During the neonatal stay, preterm infants exhibit poor growth usually due to metabolic instability in the early postnatal period and later due to reasons like feed intolerance, infection including necrotising enterocolitis or severe gastro-oesophageal reflux. Hence optimising the delivery of parenteral nutrition and/or enteral feeding should be the prime objective in this period. In infants with bronchopulmonary dysplasia, energy expenditure is higher than normal. Other situations where an iatrogenic increase in energy expenditure and thereby result in poor weight gain are both cold stress and the use of methylxanthines¹⁰. Poor growth can also be consequence of chronic hyponatraemia (infants born before 32 weeks’ gestation) and with use of postnatal steroids in the treatment of bronchopulmonary dysplasia¹¹.

Weaning on to solids
The Department of Health recommends weaning from 6 months; however some babies may be ready earlier. Weaning should not begin before 17 weeks. There is no convincing evidence that avoidance or delayed introduction of potentially allergenic foods, such as fish and eggs, reduces allergies, either in infants considered at increased risk for development of allergy or in those not considered to be at risk⁹.
Using the available data, a weaning leaflet has been designed for preterm infants; it is available from www.bliss.org.uk

Conclusion
• Later cognitive ability is related to height and head circumference in children born preterm
• Post-natal growth failure often leads to small stature and head size at school age
• Nutritional input needs to be optimised, considering the risks and benefits of promoting early rapid growth. There may be a role for specially designed formulae (like Cow & Gate Nutriprem range) to assist in catch-up growth of preterm infants where breastfeeding is not successful
• The ultimate feeding and nutritional goal is to achieve baby-led demand feeding to enable catch-up growth to occur
• There is still this unanswered question about the desirability of accelerating growth in those who are already growing satisfactorily, and about the predisposition to later adult-onset diseases


References:
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11. Gibson AT, Pearse RG, Wales JKH. Growth retardation after dexamethasone administrating assessment by knemometry. Arch Dis Child 1993; 69:505-509.