Koletzko B, Poindexter B, Uauy R (eds): Nutritional Care of Preterm Infants: Scientific Basis and Practical Guidelines. World Rev Nutr Diet. Basel, Karger, 2014, vol 110, pp 264–277 (DOI: 10.1159/000358475)

Feeding the Preterm Infant after Discharge Alexandre Lapillonne  Paris Descartes University, APHP Necker Hospital, Paris, France and CNRC, Baylor College of Medicine, Houston, Tex., USA Reviewed by Alison Leaf, National Institute for Health Research, University of Southampton, Southhampton, UK; Thibault Senterre, Department of Neonatology, University of Liège, Liège, Belgium

Abstract In recent years, much attention has been focused on enhancing the nutritional support of very preterm infants to improve both survival and quality of life. In most countries throughout the world, preterm infants tend to be discharged from hospital earlier than the expected term for economic and other reasons. The question has arisen whether such infants might require special nutritional regimens or special discharge formulas. Since nutrition during hospitalization tends to improve, thereby reducing acquired nutrition deficit, the question of the systematic use of specially designed nutrient-enriched discharge formulas should be questioned. Recommendations for feeding the preterm infant after hospital discharge are made keeping in mind that the goal in nourishing preterm infants after discharge should be to promote human milk feeding, minimize nutrient deficits, promptly address these deficits once identified, and avoid over-nourishing or promoting postnatal growth © 2014 S. Karger AG, Basel acceleration once nutrient deficits have been corrected.

The very preterm infant at the time of discharge presents a nutritional challenge to healthcare providers beginning with the decisions on what type of milk should be given after discharge and on the need to continue to supplement mother’s milk. Furthermore, establishing breastfeeding is frequently problematic and because of a certain degree of immaturity, preterm infants at the time of discharge may be sleepier and have less stamina and may have more difficulty with latch, suck, and swallow than full-term infants. Any one or a combination of these conditions places the mothers and infants at risk for difficulty in establishing successful lactation or for breastfeeding failure.

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Current Practices for Feeding after Hospital Discharge

Post-discharge practices regarding breastfeeding and nutrient enrichment of feedings vary widely by country, neonatal intensive care units (NICUs) and even by the neonatologist on service. Depending on the NICU, infants could be sent home on human milk alone (breast- and/or bottle-fed), on partially or fully nutrient-fortified human milk or on nutrient-enriched or conventional term formula. Furthermore, in most countries throughout the world, preterm infants tend to be discharged from hospital earlier than the expected term for economic and other reasons. The question has arisen whether such infants might require special nutritional regimens or special discharge formulas. At the time of discharge the volume of feeds consumed varies greatly and may reach 200 ml/kg day or more if the infants are fed ad libitum. Caloric density makes a difference as infants on less caloric-dense formulas have been shown to have increased formula intake (22–23% or more) compared with infants on higher caloric dense formulas [1]. Therefore, energy density of feeding will determine in part the intake of other nutrients including proteins and macronutrients. Guidance on how to feed very low birth weight (VLBW) infants after hospital discharge is both scarce and conflicting. Although there is a lack of evidence to suggest a prescriptive approach to feeding all VLBW infants after discharge, there is general consensus in the literature that human milk should be fed in preference to infant formula and that subgroups of infants in the NICU are likely to be at the highest nutritional risk after discharge. However, since nutrition during hospitalization tends to improve, thereby reducing acquired nutrition deficit, the systematic use of specially designed nutrient-enriched discharge formulas should be questioned. Ideally, the pre- and post-discharge nutritional concerns for the low birth weight infant should be a continuum, but this is generally not the case. VLBW infants are continuing to be discharged at earlier postmenstrual ages and lower body weights, and are supervised by healthcare providers not involved with their inpatient care. Close nutritional monitoring of infants after hospital discharge is frequently not accomplished since high-risk neonatal follow-up clinics have been traditionally more concerned with neurodevelopmental rather than the nutritional follow-up of infants. Therefore, it is of significant interest to establish post-discharge feeding guidelines.

Several lines of evidence suggest that preterm infants, particularly those born of VLBW, are at greater nutritional risk at the time of hospital discharge than at birth. Extrauterine growth retardation, also called extrauterine growth restriction, postnatal growth retardation or postnatal growth failure, has been identified as a major problem secondary to suboptimal nutrition and has been reported from all over the world [2– 6]. Numerous studies have also shown an altered body composition at the time of discharge including a reduced fat-free mass [7] and an increased total [7–9] or intra-

Feeding the Preterm Infant after Discharge Koletzko B, Poindexter B, Uauy R (eds): Nutritional Care of Preterm Infants: Scientific Basis and Practical Guidelines. World Rev Nutr Diet. Basel, Karger, 2014, vol 110, pp 264–277 (DOI: 10.1159/000358475)

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Nutritional Status at Hospital Discharge

abdominal adiposity [7, 10]. This predominant fat mass deposition during postnatal life among preterm infants might be speculated to be a consequence of imbalanced nutrition during hospitalization, especially the protein/energy ratio [11]. It has also become evident that assessing growth during hospitalization should include measurements of the head circumference since it predicts long-term outcomes [12–15]. As a general principle, the earlier an infant is born before his or her expected delivery date, the greater is their risk for morbidity and malnutrition and the likelihood that not all nutrient deficits will be resolved prior to hospital discharge. Therefore, preterm infants born VLBW and particularly those born extremely low birth weight have the greatest nutrient needs especially if they are discharged home much before their expected date of delivery, are predominantly fed human milk, have fallen below the 3rd or 5th percentile on growth references or have persistent morbidities that elevate nutritional requirements or limit the volume of feeds consumed, i.e. infants with chronic lung disease and those with an uncoordinated suck swallow and/or short bowel. It should be noted that most attention has been focused on the macronutrient content of feedings that contribute to caloric intake, including protein which is very important for growth. However, attention should also be paid to other possible nutrient deficiencies which may not affect growth and hence often go undetected. Among these nutrients, specific attention should be paid to minerals, iron, long-chain polyunsaturated fatty acid, and vitamin A. It is clear that the nutritional status of preterm infants at the time of discharge is heterogeneous and that it varies according to gestational age, postnatal age, in utero growth, nutritional management during hospitalization, associated morbidities and likely genetic factors. Therefore, it is unlikely that a standardized nutritional practice may covert the need of all preterm infants after hospital discharge and an individualized approach would best meet this goal. However, common features might be identified and should be known by physicians in order to adapt their prescription and guidelines given to parents.

The World Health Organization, American Pediatric Society, Canadian Pediatrics Society, European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) and many other professional bodies globally recommend mothers’ own milk for nutrition of infants for the first 6 months of life and beyond [16–18]. These endorsements have evolved from an extensive body of literature in both term and preterm infants that support many advantages to human milk over formula feeding including improved neurodevelopment, gastrointestinal function and host defense [19– 21]. Despite the advantages of using human milk after hospital discharge, for a variety of reasons such as maternal illness, stress, lack of support and other factors related to

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Current Guidelines for Feeding the Preterm Infant after Discharge

preterm birth, rates of human milk feeding among preterm fall significantly below that of term-born infants and recommendations [22]. In its recent position statement, the ESPGHAN Committee on Nutrition concluded that infants discharged home with a normal weight for post-conceptional age are not at increased risk of long-term growth failure and could be fed similarly to term infants of similar gestational age. By contrast, those with a subnormal weight for postconceptional age are at increased risk of long-term growth failure and require particular attention and follow-up [23]. Breastfeeding and fortified human milk should be promoted and if formula-fed, a preterm formula or a special post-discharge formula with a higher concentration of protein, minerals and trace elements as well as long-chain fatty acids than standard term formula should be provided until the preterm infant reaches 40 weeks’ post-conceptional age but possibly until 52 weeks’ postconceptional age [23, 24]. The most recent edition of the Pediatric Nutrition Handbook of the American Academy of Pediatrics, unlike its predecessors, now supports the use of specially designed nutrient-enriched discharge formulas that may promote better linear growth, weight gain, and bone mineral content than standard term formula [17].

Young et al. [25] in their Cochrane review identified 15 good quality controlled trials (n = 1,128 infants) that examined the efficacy of feeding preterm infants after hospital discharge a nutrient-enriched formula compared with a standard term formula. Nutrient-enriched formulas were either preterm formulas (energy content >75 kcal/100 ml; protein content >2.0 g/100 ml) or post-discharge formulas (energy content >72 kcal/100 ml and 1.7 g/100 ml) containing additional minerals, trace elements and vitamins. Standard term formulas used in the studies contained 66–68 kcal/100 ml and 1.4–1.5 g/100 ml protein. The authors concluded that ‘current recommendations to prescribe post-discharge formula for preterm infants following hospital discharge are not supported by the available evidence’. While it is difficult to argue with their conclusions, it is important to understand that preterm infants at highest nutritional risk were either excluded or were under-represented in these analyses. For example, in 8 trials, a significant proportion of infants were born >1,500 g. Additionally, very few participants in the trials were small for gestational age at birth or enrolment. However, the analysis of the 3 trials that recruited infants growth-restricted at birth, demonstrated a statistically significant effect at 6 months corrected age on crown-heel length [8.88 (95% CI 0.94– 16.83) mm] and head circumference [5.36 (95% CI 0.62–10.11) mm] suggesting that these infants may benefit from receiving a post-discharge formula. Finally, infants with additional problems at discharge, particularly inadequate independent oral feed-

Feeding the Preterm Infant after Discharge Koletzko B, Poindexter B, Uauy R (eds): Nutritional Care of Preterm Infants: Scientific Basis and Practical Guidelines. World Rev Nutr Diet. Basel, Karger, 2014, vol 110, pp 264–277 (DOI: 10.1159/000358475)

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Evidence in Support of the Need for Nutrient-Enriched Formula after Hospital Discharge

ing or receipt of supplemental oxygen secondary to chronic lung disease, were not eligible to participate in the trials although they were very likely growth-retarded at discharge from hospital. The conclusion of the meta-analysis with regard to the effects of feeding a preterm formula after discharge is somewhat different. Indeed, there was some evidence of higher rates of growth through infancy. The infants fed the preterm formula for 2–6 months after discharge weighed ∼500 g more and were 5–10 mm taller at 12–18 months corrected age compared to infants fed a term formula. Furthermore, they exhibited a 5-cm larger head circumference since 6 months corrected age which tracked up to 18 months corrected age. Among the studies excluded from the meta-analysis, it should be noted that feeding nutrient-enriched formula without extra energy after term does not change the quantity of growth but does influence the quality of growth of preterm infants [26]. Infants fed the nutrient-enriched formula had a lower fat mass corrected for body size at 6 months corrected age than infants fed a standard formula or human milk. Similarly, preterm infants fed a preterm formula after discharge had both an increase fatfree and peripheral fat mass but not central adiposity compared to infants fed a standard term formula [27]. Similarly, another study exhibited a better weight gain, a proportional increase in fat mass and lean mass and a better bone mineral content at expected term in preterm infants fed an isocaloric preterm formula enriched with protein, calcium and phosphorus versus the control preterm formula [24]. These data provide evidence that nutrient-dense formula after discharge does not promote central adiposity in preterm infants [27] and may be beneficial in increasing immediate weight gain and mineralization. Results with regard to outcomes other than growth or body composition showed no significant effect of feeding either a post-discharge formula or a preterm formula after discharge on development (tables 1, 2). Furthermore, there is no data allowing studying the effect of feeding an enriched formula after discharge on later blood pressure or insulin resistance [25].

Although feeding human milk to VLBW infants is widely acknowledged as being superior to formula feeding, human milk-fed infants often accrue the greatest nutritional deficits by hospital discharge. The ESPGHAN Committee on Nutrition recommends that human milk-fed infants with subnormal weight for post-conceptional age consume milk after discharge that is supplemented to provide an adequate nutrient supply [23]. Very little work, to date, has been done to evaluate whether multinutrient fortification of human milk after hospital would be beneficial. Recently, a small study was conducted in which predominantly human milk-fed VLBW (750–1,800 g) pre-

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Lapillonne Koletzko B, Poindexter B, Uauy R (eds): Nutritional Care of Preterm Infants: Scientific Basis and Practical Guidelines. World Rev Nutr Diet. Basel, Karger, 2014, vol 110, pp 264–277 (DOI: 10.1159/000358475)

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Evidence in Support of the Need for Nutrient-Enriched Human Milk after Hospital Discharge

Table 1. Nutritional needs by weeks of gestation Nutritional needs per kg/day GA, weeks

Feeding the preterm infant after discharge.

In recent years, much attention has been focused on enhancing the nutritional support of very preterm infants to improve both survival and quality of ...
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