Nutrition and Growth in Primary Care of the Premature Infant

1. Nutrition and Growth in Primary Care of the Premature Infant Ma. Teresa C. Ambat, MD Neonatology-TTUHSC 10/21/2008

2. Postnatal Growth of Premature Infants • Goal of nutrition support for VLBW from birth to term: match the in utero growth rates of the normally growing fetus • This goal is rarely achieved • Problem of chronic undernutrition and poor growth • 99% of ELBW and 97% of VLBW had weights <10th percentile at 36 wks PMA

3. For each gestational age category, the postnatal study growth curve was shifted to the right of the reference curve Postnatal Growth of Premature Infants

4. Postnatal Growth of Premature Infants • Extra-uterine growth retardation • Caused by early growth delay, coupled with a lack of catch-up growth • Most frequent cause of morbidity seen in VLBW • Have long term consequences on neurodevelopmental outcomes

5. Postdischarge Nutrition of Premature Infants • Only recently that attention has been paid to nutritional support of these infants after hospital discharge • Best practice should continue to evolve • Key questions • Whether VLBW infants have special nutritional requirements in the postdischarge period and • Whether this period of nutrition is also critical for later health and development

6. ELBW, VLBW SGA, IUGR Exclusively breastfed Requiring special formulas Requiring tube feedings at home Fail to gain at least 20g/day before D/C G Tube / tracheostomies TPN >4 wks 9.Diagnosis of any of the ffg: BP Chronic renal insufficiency Congenital GI anomalies Cyanotic CHD IEM Malabsorption Osteopenia Poverty/LSES Severe neurologic impairment SBS Infants at Highest Risk for Nutritional Deficiencies after NICU Discharge

7. Human Milk for Premature Infants • Preferred feeding for ELBW/VLBW • Nutritional value • Immunologic and antimicrobial components • Contains hormones and enzymes • Once growth is established, nutritional needs of the preterm infant exceed the content of human milk for protein, Ca, P, Mg, Na, Co, Zn and vitamins

8. Human Milk for Premature Infants • Unsupplemented HM • Associated with slower growth rate • Nutritional deficiencies: hyponatremia, hypoproteinemia, osteopenia, Zn deficiency • Infants discharged with subnormal weight for CA should be supplemented • ??? continued use of HMF

9. Human Milk for Premature Infants • Transition from supplemented EBM to exclusive breastfeeding • Favorable strategy??? • Optimal supplementary/complementary feeding? • No best practice protocols

10. Human Milk for Premature Infants • Other practical points • Fresh milk may be fed immediately or refrigerated at ~40 C • Refrigerated milk should be fed within • Freezing: ~ -200 C • Frozen milk retains most of its immunologic properties and vitamin content within • Frozen milk should be thawed in cool or lukewarm running tap water or in a basin of warm water • Use of microwave not recommended • Reduces IgA levels and lyzozyme activity, produce hot spots 48 hrs 3 months

11. Postdischarge Nutrition of Premature Infants • Potential discharge strategies • Provide calorically enhanced, EBM at the energy density tolerated before D/C  gradual increase in exclusive nursing sessions (-1 bottle feeding at a time) as the infant outgrows the need for extra calories • Nurse on demand but specify a required daily intake of nutrient enriched post discharge formula (e.g. 2-3 feedings of PDF per day) • Strategy should be individualized • Collaboration with dietitian/lactation consultant

12. Postdischarge Formula for Premature Infants • Nutrient-enriched formula for preterm infants after hospital discharge - postdischarge formula (PDF) • Enfacare 22 cal, Neosure 22 cal • Intermediate in composition between preterm and term formulae • Compared to term formula, PDF contains • Increased amount of protein with sufficient additional energy • Contains extra Ca, P, Zn - necessary to promote linear growth • Additional vitamins and trace elements

13. Postdischarge Formula for Premature Infants • Use of PDF after discharge in preterm infants  improved growth, with differences in weight and length • AAP recommendations 1. Use of PDF vs term formulas to 9mos chronological age  greater linear growth, weight gain and bone mineral content 2. Iron and vitamin fortified  no other supplements 3. If average intake 150ml/k/day  +Iron 1mg/k/day until 12 mos

14. Other Infant Formulas • AAP Recommendations • No role for use of low iron formulas • Hypoallergenic formulas • HM, protein hydrolysates – may be useful in prophylaxis or eradication of symptoms in sensitized infants • No evidence to support the routine use for tx of colic, sleeplessness or irritability • Soy formulas • Carbohydrate, protein and mineral absorption and utilization not well documented in preterm • Not recommended for: PT <1800g, prevention of colic or allergy, cow-milk protein induced enterocolitis or enteropathy

15. Caloric Supplementation • Indications • Flat or decelerating growth curve pattern • Volume restricted (severe BPD, cardiac disease) • Unable to take enough • Monitor for dietary intolerance (GI symptoms, bloody stools), hydration status • If increased caloric supplementation does not improve growth  further evaluation by endo, GI, dietitian

16. Caloric Supplementation

17. Caloric Supplementation • Weaning • Gradual adjustments to caloric density followed by weight checks • Serial measurements of growth (adjusting for prematurity) including length and HC • Breastfed: assessment of infant’s ability to transfer sufficient quantities of milk as well as adequacy of mother’s milk supply • Formula-fed: assessment of infant’s volume intake

18. Micronutrient Supplementation • No guidelines for supplementing premature infants with water-soluble vitamins after discharge • Supplementation until 1 yr chronological age is not unreasonable • PDF supply more water-soluble vitamins > term formulas • Little info about supplementation of fat-soluble vitamins • For HM fed, oral solutions of A,D,E available • PDF supply adequate amounts of fat-soluble vitamins • For healthy PT, probably not necessary to supplement after attaining weight of 3 kg

19. Micronutrient Supplementation • If on EPO: give 6mg/k/day • Most standard MVI prep contains 400 IU per mL • If weaned to at least 500mL per day of Vit-D fortified formula, this may be d/cd

20. Micronutrient Supplementation • Calcium and Phosphorus • Continued use of nutrient enriched formulas in PT until 9 mos  improved bone mineral content • Greater challenge in breastfed former PT (2-3 feedings of PDF per day may enhance mineral intake) • Infant with hx of osteopenia (separate discussion) • Fluoride • Supplementation should be based on total amount of fluoride from all sources available

21. Micronutrient Supplementation • Trace minerals • Zinc: PTF, TF and HMF provide sufficient Zn • Copper: RDI can be met by HM or PTF • Iodine: all formula for PT will supply RDI HM will not supply enough iodine by itself, though supplementation has not been established 4. Selenium, chromium, molybdenum or manganese: deficiency in PT has not been reported

23. Most optimal strategies for the postdischarge nutritional management of ELBW/VLBW are unknown • Further research needed to determine best practice guidelines • Serial measurements of growth and maintaining postdischarge feedings may offer favorable strategy until more specific, universally accepted protocols are established

24. Complimentary Feeding 1. Introduce solid foods when the infant is developmentally ready, generally between 4-6 months • No nutritional indication to add complimentary foods to diet of the healthy term infant <4 months of age 2. Introduce new foods slowly enough so that any allergic reaction or intolerance to food can be identified • AAP: no more than 3 foods be introduced/ week • No particular order • Meat has an advantage of providing iron and zinc

25. Complimentary Feeding 3. Juice should not be introduced into the diet of infants < 6 months (risk that juice will displace BM or formula  reduced intake of protein, fat, vitamins and minerals) • Fruit juices should be limited to 4-6oz/day after 6 months • Neither breastfed nor formula-fed require extra water 4. Do not give cow’s milk before 12 months, because it may adversely affect the infant’s iron status 5. Do not give reduced-fat cow’s milk to children < 2years (children at this age should not have fat-restricted diet)

26. Complimentary Feeding 6. Offer fruits and vegetables to infants daily beginning at 6-8 months 7. Limit the amount of salt added to foods fed to infants • When salt is used, use iodized salt 8. Limit consumption of low-nutrient foods

27. References • Pediatric Nutrition Handbook • Primary Care of the Premature Infant