Premature infants fed mothers' milk to 6 months corrected age demonstrate adequate growth and zinc status in the first year

Association of serum and erythrocyte zinc levels with breastfeeding and complementary feeding in preterm and term infants

Zinc is an important nutrient involved in cell division, physical growth, and immune system function. Most studies evaluating the nutritional status related to zinc and prematurity were conducted with hospitalized preterm infants. These studies show controversial results regarding the prevalence of deficiency, clinical implications, and the effect of zinc supplementation on mortality, infectious diseases, and growth in these groups. This study aimed to compare serum and erythrocyte zinc levels in a group of preterm and full-term infants after 9 months of age, and related the zinc levels to dietary intake and anthropometric indicators in both groups. This cross-sectional study compared 43 preterm infants (24 to 33 weeks) aged 9-24 months to 47 full-term healthy infants. Outcome measures: anthropometric indicators and dietary intake. Blood sample for serum and erythrocyte zinc levels (ICP-MS, Inductively Coupled Plasma Mass Spectrometry). There was no difference between the groups regarding the mean of serum and erythrocyte zinc. Variables associated with higher serum zinc levels were breastfeeding at evaluation (β = 20.11 µg/dL, 95% CI 9.62-30.60, p < 0.001) and the later introduction of solid foods (β = 6.6 µg/dL, 95% CI 5.3-11.4, p < 0.001). Breastfeeding was also associated with higher erythrocyte zinc levels. The zinc levels were adequate in both groups, there was no association with anthropometric indicators or dietary intake and were slightly influenced by breastfeeding and time of solid food introduction.

Multi-nutrient fortification of human milk for preterm infants

BACKGROUND

Human breast milk-fed preterm infants can accumulate nutrient deficits leading to extrauterine growth restriction. Feeding preterm infants with multi-nutrient fortified human milk could increase nutrient accretion and growth rates and improve neurodevelopmental outcomes. Concern exists, however, that multi-nutrient fortifiers are associated with adverse events such as feed intolerance and necrotising enterocolitis.

OBJECTIVES

To determine whether multi-nutrient fortified human milk, compared with unfortified human milk, affects important outcomes (including growth rate and neurodevelopment) of preterm infants without increasing the risk of adverse effects (such as feed intolerance and necrotising enterocolitis).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 9), MEDLINE via PubMed (1966 to 26 September 2019), Embase (1980 to 26 September 2019), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 26 September 2019). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared feeding preterm infants with multi-nutrient (protein and energy plus minerals, vitamins, or other nutrients) fortified human breast milk versus unfortified (no added protein or energy) breast milk.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal. Two review authors separately evaluated trial quality, extracted data, and synthesised effect estimates using risk ratios (RRs), risk differences, and mean differences (MDs). We assessed the certainty of the body of evidence at the outcome level using "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) methods.

MAIN RESULTS

We identified 18 trials in which a total of 1456 preterm infants participated. These trials were generally small and methodologically weak. Meta-analyses provided low- to moderate-certainty evidence showing that multi-nutrient fortification of human milk increases in-hospital rate of weight gain (MD 1.76 g/kg/d, 95% confidence interval (CI) 1.30 to 2.22), body length (MD 0.11 cm/week, 95% CI 0.08 to 0.15), or head circumference (MD 0.06 cm/week, 95% CI 0.03 to 0.08) among preterm infants. Few data on growth and developmental outcomes assessed beyond infancy are available, and these do not show effects of multi-nutrient fortification. The data do not suggest other benefits or harms and provide low-certainty evidence suggesting effects of multi-nutrient fortification on the risk of necrotising enterocolitis in preterm infants (typical RR 1.37, 95% CI 0.72 to 2.63; 13 studies, 1110 infants).

AUTHORS' CONCLUSIONS

Feeding preterm infants with multi-nutrient fortified human breast milk compared with unfortified human breast milk is associated with modest increases in in-hospital growth rates. Evidence is insufficient to show whether multi-nutrient fortification has any effect on long-term growth or neurodevelopment.

Multi-nutrient fortification of human milk for preterm infants

BACKGROUND

Exclusively breast milk-fed preterm infants may accumulate nutrient deficits leading to extrauterine growth restriction. Feeding preterm infants with multi-nutrient fortified human breast milk rather than unfortified breast milk may increase nutrient accretion and growth rates and may improve neurodevelopmental outcomes.

OBJECTIVES

To determine whether multi-nutrient fortified human breast milk improves important outcomes (including growth and development) over unfortified breast milk for preterm infants without increasing the risk of adverse effects (such as feed intolerance and necrotising enterocolitis).

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2), MEDLINE, EMBASE and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (until February 2016), as well as conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared feeding preterm infants with multi-nutrient (protein and energy plus minerals, vitamins or other nutrients) fortified human breast milk versus unfortified (no added protein or energy) breast milk.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group. We separately evaluated trial quality, data extracted by two review authors and data synthesised using risk ratios (RRs), risk differences and mean differences (MDs). We assessed the quality of evidence at the outcome level using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We identified 14 trials in which a total of 1071 infants participated. The trials were generally small and weak methodologically. Meta-analyses provided low-quality evidence that multi-nutrient fortification of breast milk increases in-hospital rates of growth (MD 1.81 g/kg/d, 95% confidence interval (CI) 1.23 to 2.40); length (MD 0.12 cm/wk, 95% CI 0.07 to 0.17); and head circumference (MD 0.08 cm/wk, 95% CI 0.04 to 0.12). Only very limited data are available for growth and developmental outcomes assessed beyond infancy, and these show no effects of fortification. The data did not indicate other potential benefits or harms and provided low-quality evidence that fortification does not increase the risk of necrotising enterocolitis in preterm infants (typical RR 1.57, 95% CI 0.76 to 3.23; 11 studies, 882 infants).

AUTHORS' CONCLUSIONS

Limited available data do not provide strong evidence that feeding preterm infants with multi-nutrient fortified breast milk compared with unfortified breast milk affects important outcomes, except that it leads to slightly increased in-hospital growth rates.

Zinc and copper concentrations in human preterm milk

Zinc and copper are important trace elements in the nutrition of preterm infants. This study determined and compared the concentrations of zinc and copper in preterm milk of mothers receiving and not receiving zinc supplementation diets. The effects of maternal supplementation on the blood levels and anthropometric parameters were evaluated. Thirty-eight mothers and their preterm infants were enrolled in the study. Eighteen mothers were given a daily supplementation of 50 mg zinc, whereas the other 20 were not. Zinc and copper levels in milk were determined at 15-day intervals, as were blood zinc levels along with anthropometric parameters. Zinc and copper contents were determined by atomic absorption spectrophotometry. No significant differences were found between groups either for zinc values in maternal milk and infant blood or for anthropometric measurements. A pronounced decrease in copper levels was observed in mothers receiving supplemental zinc. Zinc supplementation given to mothers who were breastfeeding preterm infants had no significant effect on zinc secretion in milk.

An objective means of diagnosing anorexia nervosa and bulimia nervosa using 15N/14N and 13C/12C ratios in hair

An objective means based on the carbon and nitrogen stable isotope analysis of five hairs per individual is presented for distinguishing between individuals with anorexia nervosa and/or bulimia nervosa from non-clinical individuals (i.e. clinically normal controls). Using discriminant analysis, an algorithm has been developed that provides both sensitivity and specificity of 80% in making diagnoses of individuals with these eating disorders. With further refinements, the results suggest that it may be also possible to distinguish between individuals with anorexia or bulimia. Finally, the study shows the value of conducting blind tests and using larger sample sizes of both control and treatment groups. Both groups are needed to validate the diagnostic value of a method and to provide measures of sensitivity and specificity of any diagnostic test.

Infusionstherapie und Ernährung von Risikogruppen

Besondere Situationen erfordern ein besonderes Vorgehen. Während bisher das »Standardvorgehen« bezüglich der Ernährung von pädiatrischen Patienten dargestellt wurde, beschäftigt sich das vorliegende Kapitel mit »Sondersituationen« der pädiatrischen Infusionstherapie und Ernährung. Behandlungssituationen, die ein besonderes Vorgehen bei der Therapie oder spezielle Aufmerksamkeit bei der Anpassung der Ernährung erfordern, entstehen in der Regel durch 4 mögliche Situationen:

spezifische Physiologie von Patientengruppen (z. B. Früh- oder Neugeborene),

Auswirkungen von therapeutischen Maßnahmen (z. B. Operationen),

Pathophysiologie von Erkrankungen (z. B. angeborene Stoffwechselerkrankungen, Erkrankungen des onkologischen, rheumatischen oder atopischen Formenkreises, Anorexia nervosa, Bulimie oder Adipositas) oder

besondere körperliche Belastungen [z. B. (Leistungs-)Sport].

Bekannte Strategien werden systematisch und prägnant dargestellt und diskutiert.

Die Beschäftigung mit der Ernährung von »Risikogruppen« übt das Erkennen und den Umgang von potenziellen Gefahrensituationen bei der Verordnung von bilanzierter Ernährung. So sollte auch derjenige von dem Kapitel profitieren, der sich mit den behandelten Patientengruppen, Situationen, Erkrankungen üblicherweise nicht beschäftigen muss.

Nutrition for preterm infants after hospital discharge

Preterm infants accrue significant nutrient deficits during hospitalization, and at the time of discharge most VLBW preterm infants have moderate to severe growth failure. Infants with significant morbidities and infants with ELBW have more severe growth failure since they regain birth weight at a later age, and they gain weight more slowly. Catch-up growth accelerates after hospital discharge. The rates of catch-up growth vary according to many factors including birth weight, gestational age, parental size, adequacy of intrauterine growth, neurologic impairment, clinical course, and nutrition. Most catch-up growth occurs within the first 2 to 3 years of life; however, compensatory catch-up growth may continue into adolescence and adulthood. Despite evidence of ongoing catch-up growth, the mean growth measurements of children and adults who were born preterm and with VLBW are lower than their term-born peers. Accelerated rates of catch-up growth are associated with better neurodevelopmental outcomes. Inadequate head circumference growth, in particular, may have long-term prognostic significance for later neurodevelopment in preterm infants. Nutrient-enriched formulas that provide 22 kcal/oz are often prescribed for VLBW preterm infants after hospital discharge. Several studies have reported that preterm infants fed the enriched versus standard term infant formulas have greater rates of catch-up growth during the first year of life, including greater increases in head circumference. The nutrient-enriched formulas appear to be of particular benefit for male infants. There is less information regarding the nutrient needs of breast-fed infants after hospital discharge. However, several studies have demonstrated that preterm infants fed unfortified human milk after discharge have growth rates and bone mass that are lower than formula-fed infants during infancy. The use of fortified human milk, or alternate feedings with a nutrient-enriched formula may be useful for breast-fed infants who have delays in catch-up growth. Additional studies are needed to determine whether enriched feedings might be of particular benefit for preterm infants who are at greater risk for postnatal growth failure, including infants born SGA, or with extremely low birth weights, intrauterine growth restriction, or chronic conditions such as bronchopulmonary dysplasia. The potential effect of nutritional programming on long-term outcomes of preterm infants also requires further investigation.

Multicomponent fortified human milk for promoting growth in preterm infants

BACKGROUND

For term infants, human milk provides adequate nutrition to facilitate growth, as well as potential beneficial effects on immunity and the maternal-infant emotional state. However, the role of human milk in premature infants is less well defined as it contains insufficient quantities of some nutrients to meet the estimated needs of the infant. Observational studies have suggested that infants fed formula have a higher rate of growth than infants who are breast fed. However, there are potential short term and long term benefits from human milk. Commercially-produced multicomponent fortifiers provide additional nutrients to supplement human milk (in the form of protein, calcium, phosphate, and carbohydrate, as well as vitamins and trace minerals).

OBJECTIVES

The main objective was to determine if addition of multicomponent nutritional supplements to human milk leads to improved growth, bone metabolism and neurodevelopmental outcomes without significant adverse effects in premature infants.

SEARCH STRATEGY

Searches were made of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 3003), MEDLINE (searched August 29, 2003), previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants, journal handsearching mainly in the English language.

SELECTION CRITERIA

All trials utilising random or quasi-random allocation to supplementation of human milk with multiple nutrients or no supplementation in premature infants within a nursery setting were eligible.

DATA COLLECTION AND ANALYSIS

Data were extracted using the standard methods of the Cochrane Collaboration and its Neonatal Review Group, with separate evaluation of trial quality and data extraction by each author and synthesis of data using relative risk and weighted mean difference.

MAIN RESULTS

Supplementation of human milk with multicomponent fortifiers is associated with short term increases in weight gain, linear and head growth. There is no effect on serum alkaline phosphatase levels; it is not clear if there is an effect on bone mineral content. Nitrogen retention and blood urea levels appear to be increased. There are insufficient data to evaluate long term neurodevelopmental and growth outcomes, although there appears to be no effect on growth beyond one year of life. Use of multicomponent fortifiers does not appear to be associated with adverse effects, although the total number of infants studied and the large amount of missing data reduces confidence in this conclusion. Blood urea levels are increased and blood pH levels minimally decreased, but the clinical significance of this is uncertain.

REVIEWER'S CONCLUSIONS

Multicomponent fortification of human milk is associated with short-term improvements in weight gain, linear and head growth. Despite the absence of evidence of long-term benefit and insufficient evidence to be reassured that there are no deleterious effects, it is unlikely that further studies evaluating fortification of human milk versus no supplementation will be performed. Further research should be directed toward comparisons between different proprietary preparations and evaluating both short-term and long-term outcomes in search of the "optimal" composition of fortifiers.

Calcium, magnesium, phosphorus and vitamin D fortification of complementary foods

Provision of the bone minerals and vitamin D as fortificants in food or as dietary supplements designed for older infants and toddlers in Latin America is likely to be beneficial and safe. Currently available data are inadequate to establish the precise amounts of these nutrients that would be required for such a supplement. These amounts would vary according to the local base diet. However, reasonable estimates can be made on the basis of current dietary recommendations as well as existing data on bioavailability and customary intake. The strongest case can be made for calcium and vitamin D supplementation. Because excessive dietary calcium can reduce zinc absorption as a result of interactive effects within the intestine, an appropriate ratio of calcium to zinc should be used, even if this means adding zinc as a fortificant or supplement. Magnesium supplementation may be appropriate in some circumstances but it cannot be routinely advocated at present. It is unlikely that phosphorus supplementation is needed for most population groups because of the relatively high usual dietary phosphorus intakes, primarily from phosphate salts added to carbonated beverages and as food preservatives.

Nutrient requirements for preterm infant formulas

Achieving appropriate growth and nutrient accretion of preterm and low birth weight (LBW) infants is often difficult during hospitalization because of metabolic and gastrointestinal immaturity and other complicating medical conditions. Advances in the care of preterm-LBW infants, including improved nutrition, have reduced mortality rates for these infants from 9.6 to 6.2% from 1983 to 1997. The Food and Drug Administration (FDA) has responsibility for ensuring the safety and nutritional quality of infant formulas based on current scientific knowledge. Consequently, under FDA contract, an ad hoc Expert Panel was convened by the Life Sciences Research Office of the American Society for Nutritional Sciences to make recommendations for the nutrient content of formulas for preterm-LBW infants based on current scientific knowledge and expert opinion. Recommendations were developed from different criteria than that used for recommendations for term infant formula. To ensure nutrient adequacy, the Panel considered intrauterine accretion rate, organ development, factorial estimates of requirements, nutrient interactions and supplemental feeding studies. Consideration was also given to long-term developmental outcome. Some recommendations were based on current use in domestic preterm formula. Included were recommendations for nutrients not required in formula for term infants such as lactose and arginine. Recommendations, examples, and sample calculations were based on a 1000 g preterm infant consuming 120 kcal/kg and 150 mL/d of an 810 kcal/L formula. A summary of recommendations for energy and 45 nutrient components of enteral formulas for preterm-LBW infants are presented. Recommendations for five nutrient:nutrient ratios are also presented. In addition, critical areas for future research on the nutritional requirements specific for preterm-LBW infants are identified.

Nutritional zinc balance in extremely low-birth-weight infants

BACKGROUND

Zinc is important for metabolism, cell growth, immunity, and defense against oxygen radicals. Extremely low-birth-weight (< 1000 g) infants have higher nutritional needs, but information on zinc is scarce. The authors performed nutritional balances in 10 infants with birth weights of 500 to 999 g and who were fed with fortified human milk.

METHODS

The authors collected infant feces, urine, and blood and human milk samples during 72 hours at 7 and 12 weeks of age. Zinc concentration was measured by inductively coupled plasma-mass spectrophotometry, atomic emission spectrophotometry, and instrumental neutron activation analysis.

RESULTS

Mean (SD) intake via human milk was 379 (+/- 373) microg x kg(-1) x d(-1) during both balances. Urinary excretion was high at 7 weeks of age, decreased to half at 12 week, and was negatively correlated (P < 0.01) with weight gain. Mean absorption was slightly positive at 7 weeks of age but zero or negative in most infants at 12 weeks of age. Retention was negative in all infants at both observation periods, except in one infant during the second balance. Clinical zinc deficiency developed in one infant at 12 weeks of age.

CONCLUSIONS

Zinc balances in extremely low-birth-weight infants are highly variable and usually negative. Controlled trials are needed to assess need for and benefits and risks of zinc supplementation.