Nutrition of very low birth weight infants fed human milk with or without supplemental trace elements: a randomized controlled trial

Effects of Antioxidant Intake on Fetal Development and Maternal/Neonatal Health during Pregnancy

During pregnancy, cycles of hypoxia and oxidative stress play a key role in the proper development of the fetus. Hypoxia during the first weeks is crucial for placental development, while the increase in oxygen due to the influx of maternal blood stimulates endothelial growth and angiogenesis. However, an imbalance in the number of oxidative molecules due to endogenous or exogenous factors can overwhelm defense systems and lead to excessive production of reactive oxygen species (ROS). Many pregnancy complications, generated by systemic inflammation and placental vasoconstriction, such as preeclampsia (PE), fetal growth restriction (FGR) and preterm birth (PTB), are related to this increase of ROS. Antioxidants may be a promising tool in this population. However, clinical evidence on their use, especially those of natural origin, is scarce and controversial. Following PRISMA methodology, the current review addresses the use of natural antioxidants, such as epigallocatechin gallate (EGCG), melatonin and resveratrol (RESV), as well as other classical antioxidants (vitamin C and E) during the prenatal period as treatment of the above-mentioned complications. We review the effect of antioxidant supplementation on breast milk in lactating mothers.

Comparison of different protein concentrations of human milk fortifier for promoting growth and neurological development in preterm infants

BACKGROUND

Human milk alone may provide inadequate amounts of protein to meet the growth requirements of preterm infants because of restrictions in the amount of fluid they can tolerate. It has become common practice to feed preterm infants with breast milk fortified with protein and other nutrients but there is debate about the optimal concentration of protein in commercially available fortifiers.

OBJECTIVES

To compare the effects of different protein concentrations in human milk fortifier, fed to preterm infants, on growth and neurodevelopment.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search CENTRAL (2019, Issue 8), Ovid MEDLINE and CINAHL on 15 August 2019. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included all published and unpublished randomised, quasi-randomised and cluster-randomised trials comparing two different concentrations of protein in human milk fortifier. We included preterm infants (less than 37 weeks' gestational age). Participants may have been exclusively fed human milk or have been supplemented with formula. The concentration of protein was classified as low (< 1g protein/100 mL expressed breast milk (EBM)), moderate (≥ 1g to < 1.4g protein/100 mL EBM) or high (≥ 1.4g protein/100 mL EBM). We excluded trials that compared two protein concentrations that fell within the same category.

DATA COLLECTION AND ANALYSIS

We undertook data collection and analyses using the standard methods of Cochrane Neonatal. Two review authors independently evaluated trials. Primary outcomes included growth, neurodevelopmental outcome and mortality. Data were synthesised using risk ratios (RR), risk differences and mean differences (MD), with 95% confidence intervals (CI). We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We identified nine trials involving 861 infants. There is one trial awaiting classification, and nine ongoing trials. The trials were mostly conducted in infants born < 32 weeks' gestational age or < 1500 g birthweight, or both. All used a fortifier derived from bovine milk. Two trials fed infants exclusively with mother's own milk, three trials gave supplementary feeds with donor human milk and four trials supplemented with preterm infant formula. Overall, trials were small but generally at low or unclear risk of bias. High versus moderate protein concentration of human milk fortifier There was moderate certainty evidence that a high protein concentration likely increased in-hospital weight gain compared to moderate concentration of human milk fortifier (MD 0.66 g/kg/day, 95% CI 0.51 to 0.82; trials = 6, participants = 606). The evidence was very uncertain about the effect of high versus moderate protein concentration on length gain (MD 0.01 cm/week, 95% CI -0.01 to 0.03; trials = 5, participants = 547; very low certainty evidence) and head circumference gain (MD 0.00 cm/week, 95% CI -0.01 to 0.02; trials = 5, participants = 549; very low certainty evidence). Only one trial reported neonatal mortality, with no deaths in either group (participants = 45). Moderate versus low protein concentration of human milk fortifier A moderate versus low protein concentration fortifier may increase weight gain (MD 2.08 g/kg/day, 95% CI 0.38 to 3.77; trials = 2, participants = 176; very low certainty evidence) with little to no effect on head circumference gain (MD 0.13 cm/week, 95% CI 0.00 to 0.26; I² = 85%; trials = 3, participants = 217; very low certainty evidence), but the evidence is very uncertain. There was low certainty evidence that a moderate protein concentration may increase length gain (MD 0.09 cm/week, 95% CI 0.05 to 0.14; trials = 3, participants = 217). Only one trial reported mortality and found no difference between groups (RR 0.48, 95% CI 0.05 to 5.17; participants = 112). No trials reported long term growth or neurodevelopmental outcomes including cerebral palsy and developmental delay.

AUTHORS' CONCLUSIONS

Feeding preterm infants with a human milk fortifier containing high amounts of protein (≥ 1.4g/100 mL EBM) compared with a fortifier containing moderate protein concentration (≥ 1 g to < 1.4 g/100 mL EBM) results in small increases in weight gain during the neonatal admission. There may also be small increases in weight and length gain when infants are fed a fortifier containing moderate versus low protein concentration (< 1 g protein/100 mL EBM). The certainty of this evidence is very low to moderate; therefore, results may change when the findings of ongoing studies are available. There is insufficient evidence to assess the impact of protein concentration on adverse effects or long term outcomes such as neurodevelopment. Further trials are needed to determine whether modest increases in weight gain observed with higher protein concentration fortifiers are associated with benefits or harms to long term growth and neurodevelopment.

Food fortification with multiple micronutrients: impact on health outcomes in general population

BACKGROUND

Vitamins and minerals are essential for growth and maintenance of a healthy body, and have a role in the functioning of almost every organ. Multiple interventions have been designed to improve micronutrient deficiency, and food fortification is one of them.

OBJECTIVES

To assess the impact of food fortification with multiple micronutrients on health outcomes in the general population, including men, women and children.

SEARCH METHODS

We searched electronic databases up to 29 August 2018, including the Cochrane Central Register of Controlled Trial (CENTRAL), the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register and Cochrane Public Health Specialised Register; MEDLINE; Embase, and 20 other databases, including clinical trial registries. There were no date or language restrictions. We checked reference lists of included studies and relevant systematic reviews for additional papers to be considered for inclusion.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-RCTs, quasi-randomised trials, controlled before-after (CBA) studies and interrupted time series (ITS) studies that assessed the impact of food fortification with multiple micronutrients (MMNs). Primary outcomes included anaemia, micronutrient deficiencies, anthropometric measures, morbidity, all-cause mortality and cause-specific mortality. Secondary outcomes included potential adverse outcomes, serum concentration of specific micronutrients, serum haemoglobin levels and neurodevelopmental and cognitive outcomes. We included food fortification studies from both high-income and low- and middle-income countries (LMICs).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened, extracted and quality-appraised the data from eligible studies. We carried out statistical analysis using Review Manager 5 software. We used random-effects meta-analysis for combining data, as the characteristics of study participants and interventions differed significantly. We set out the main findings of the review in 'Summary of findings' tables, using the GRADE approach.

MAIN RESULTS

We identified 127 studies as relevant through title/abstract screening, and included 43 studies (48 papers) with 19,585 participants (17,878 children) in the review. All the included studies except three compared MMN fortification with placebo/no intervention. Two studies compared MMN fortification versus iodised salt and one study compared MMN fortification versus calcium fortification alone. Thirty-six studies targeted children; 20 studies were conducted in LMICs. Food vehicles used included staple foods, such as rice and flour; dairy products, including milk and yogurt; non-dairy beverages; biscuits; spreads; and salt. Fourteen of the studies were fully commercially funded, 13 had partial-commercial funding, 14 had non-commercial funding and two studies did not specify the source of funding. We rated all the evidence as of low to very low quality due to study limitations, imprecision, high heterogeneity and small sample size. When compared with placebo/no intervention, MMN fortification may reduce anaemia by 32% (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.56 to 0.84; 11 studies, 3746 participants; low-quality evidence), iron deficiency anaemia by 72% (RR 0.28, 95% CI 0.19 to 0.39; 6 studies, 2189 participants; low-quality evidence), iron deficiency by 56% (RR 0.44, 95% CI 0.32 to 0.60; 11 studies, 3289 participants; low-quality evidence); vitamin A deficiency by 58% (RR 0.42, 95% CI 0.28 to 0.62; 6 studies, 1482 participants; low-quality evidence), vitamin B2 deficiency by 64% (RR 0.36, 95% CI 0.19 to 0.68; 1 study, 296 participants; low-quality evidence), vitamin B6 deficiency by 91% (RR 0.09, 95% CI 0.02 to 0.38; 2 studies, 301 participants; low-quality evidence), vitamin B12 deficiency by 58% (RR 0.42, 95% CI 0.25 to 0.71; 3 studies, 728 participants; low-quality evidence), weight-for-age z-scores (WAZ) (mean difference (MD) 0.1, 95% CI 0.02 to 0.17; 8 studies, 2889 participants; low-quality evidence) and weight-for-height/length z-score (WHZ/WLZ) (MD 0.1, 95% CI 0.02 to 0.18; 6 studies, 1758 participants; low-quality evidence). We are uncertain about the effect of MMN fortification on zinc deficiency (RR 0.84, 95% CI 0.65 to 1.08; 5 studies, 1490 participants; low-quality evidence) and height/length-for-age z-score (HAZ/LAZ) (MD 0.09, 95% CI 0.01 to 0.18; 8 studies, 2889 participants; low-quality evidence). Most of the studies in this comparison were conducted in children. Subgroup analyses of funding sources (commercial versus non-commercial) and duration of intervention did not demonstrate any difference in effects, although this was a relatively small number of studies and the possible association between commercial funding and increased effect estimates has been demonstrated in the wider health literature. We could not conduct subgroup analysis by food vehicle and funding; since there were too few studies in each subgroup to draw any meaningful conclusions. When we compared MMNs versus iodised salt, we are uncertain about the effect of MMN fortification on anaemia (R 0.86, 95% CI 0.37 to 2.01; 1 study, 88 participants; very low-quality evidence), iron deficiency anaemia (RR 0.40, 95% CI 0.09 to 1.83; 2 studies, 245 participants; very low-quality evidence), iron deficiency (RR 0.98, 95% CI 0.82 to 1.17; 1 study, 88 participants; very low-quality evidence) and vitamin A deficiency (RR 0.19, 95% CI 0.07 to 0.55; 2 studies, 363 participants; very low-quality evidence). Both of the studies were conducted in children. Only one study conducted in children compared MMN fortification versus calcium fortification. None of the primary outcomes were reported in the study. None of the included studies reported on morbidity, adverse events, all-cause or cause-specific mortality.

AUTHORS' CONCLUSIONS

The evidence from this review suggests that MMN fortification when compared to placebo/no intervention may reduce anaemia, iron deficiency anaemia and micronutrient deficiencies (iron, vitamin A, vitamin B2 and vitamin B6). We are uncertain of the effect of MMN fortification on anthropometric measures (HAZ/LAZ, WAZ and WHZ/WLZ). There are no data to suggest possible adverse effects of MMN fortification, and we could not draw reliable conclusions from various subgroup analyses due to a limited number of studies in each subgroup. We remain cautious about the level of commercial funding in this field, and the possibility that this may be associated with higher effect estimates, although subgroup analysis in this review did not demonstrate any impact of commercial funding. These findings are subject to study limitations, imprecision, high heterogeneity and small sample sizes, and we rated most of the evidence low to very low quality. and hence no concrete conclusions could be drawn from the findings of this review.

Zinc concentration in preterm newborns at term age, a prospective observational study

OBJECTIVES

To determine zinc concentrations and associated factors in a population of preterm newborns at term age.

DESIGN

This analytical, descriptive, observational and prospective study was conducted in the neonatal unit of a tertiary hospital. Preterm newborn between gestational weeks 24 and 34 were included in the study. The patients were recruited close to the date of birth. Their clinical histories were collected, and the serum zinc concentrations (SZCs) at gestational weeks 37-41 were measured. This study aimed to measure SZC in a population of preterm newborns at term age, and analyse the anthropometric, clinical and nutritional parameters associated with a decrease in SZC.

RESULTS

Overall, 83 preterm subjects were evaluated, including 44 (53%) female infants and 39 (47%) male infants. The median period of gestation was 31 (IQ25-IQ75: 29-33) weeks, and the mean weight at birth was 1.523±0.535 kg. The median SZC at term was 4.4 (IQ25-IQ75: 2.6-6.9) µmol/L. There were some variables associated with zinc concentrations like bronchopulmonary dysplasia (BPD), weight at birth, z-score of length at discharge, being small for gestational age and treatment with recombinant human erythropoietin, although the unique variable that was independent of the other variables in the multivariate analysis (p 0.01) was BPD. Preterm newborn with BPD had lower SZC at term age than those without (2.7 vs 4.9 µmol/L, p 0.005).

CONCLUSIONS

Zinc concentrations in this preterm population were low. BPD was significantly and negatively correlated with zinc concentrations.

CLINICAL TRIAL REGISTRATION

NCT03532555.

Trace elements, oxidative status and antioxidant capacity as biomarkers in very low birth weight infants

Reference data on trace elements, oxidative status and antioxidants in very low birth weight infants (VLBW) are limited and need to be updated for use in clinical settings. Serum and urine of 30 VLBW infants (mean weight, 1167g) at mean age of 23.8 (t0) and 37.8 (t1) days were analyzed. Cadmium (Cd), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), selenium (Se) and zinc (Zn), nitrate/nitrite (NOx), catalase (CAT), CuZnFeMn-superoxide dismutases (CuZnFeMn-SODs), total antioxidant capacity (SAC: sum of thiols, proteins, bilirubin, uric acid, β-beta-carotene, ascorbic acid, vitamin E) and total oxidative status (SOS: sum of lipo- and hydroperoxides) were determined. A higher urinary excretion of Cu and Zn was observed at t0 than at t1; while an increase in urine Cd was found at t1 respect to t0. A deficiency in serum levels of Cu and Zn was also found. A lower CAT activity, a higher total oxidants level (SOS) and a reduction of total antioxidant barriers (SAC) were observed in some infants. No Fe and Mn deficiency or Hg overload was found; also CuZnFeMn-SODs and NOx levels did not change. The findings showed that losses of trace elements and incomplete mineral body stores were more pronounced in the earlier life stage (at 23.8th day) than later on; moreover, antioxidant defenses were poor and lipo- and hydroperoxides were higher still at 5 weeks of infants' life.

Enteral zinc supplementation and growth in extremely-low-birth-weight infants with chronic lung disease

OBJECTIVE

Zinc deficiency causes growth deficits. Extremely-low-birth-weight (ELBW) infants with chronic lung disease (CLD), also known as bronchopulmonary dysplasia, experience growth failure and are at risk for zinc deficiency. We hypothesized that enteral zinc supplementation would increase weight gain and linear growth.

METHODS

A cohort of infants was examined retrospectively at a single center between January 2008 and December 2011. CLD was defined as the need for oxygen at 36 weeks postmenstrual age. Zinc supplementation was started in infants who had poor weight gain. Infants' weight gain and linear growth were compared before and after zinc supplementation using the paired t test.

RESULTS

A total of 52 ELBW infants with CLD met entry criteria. Mean birth weight was 682 ± 183 g, and gestational age was 25.3 ± 2 weeks. Zinc supplementation started at postmenstrual age 33 ± 2 weeks. Most infants received fortified human milk. Weight gain increased from 10.9 before supplementation to 19.9 g · kg(-1) · day(-1) after supplementation (P < 0.0001). Linear growth increased from 0.7 to 1.1 cm/week (P = 0.001).

CONCLUSIONS

Zinc supplementation improved growth in ELBW infants with CLD receiving human milk. Further investigation is warranted to reevaluate zinc requirements, markers, and balance.

Zinc supplementation reduces morbidity and mortality in very-low-birth-weight preterm neonates: a hospital-based randomized, placebo-controlled trial in an industrialized country

BACKGROUND

Zinc plays a pivotal role in the pathogenesis of many diseases and in body growth. Preterm neonates have high zinc requirements.

OBJECTIVE

The objective of the study was to investigate the efficacy of zinc supplementation in reducing morbidity and mortality in preterm neonates and to promote growth.

DESIGN

This was a prospective, double-blind, randomized controlled study of very-low-birth-weight preterm neonates randomly allocated on the seventh day of life to receive (zinc group) or not receive (control group) oral zinc supplementation. Total prescribed zinc intake ranged from 9.7 to 10.7 mg/d in the zinc group and from 1.3 to 1.4 mg/d in the placebo control group. The main endpoint was the rate of neonates with ≥ 1 of the following morbidities: late-onset sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, periventricular leucomalacia, and retinopathy of prematurity. Secondary outcomes were mortality and body growth.

RESULTS

We enrolled 97 neonates in the zinc group and 96 in the control group. Morbidities were significantly lower in the zinc group (26.8% compared with 41.7%; P = 0.030). The occurrence of necrotizing enterocolitis was significantly higher in the control group (6.3% compared with 0%; P = 0.014). Mortality risk was higher in the placebo control group (RR: 2.37; 95% CI: 1.08, 5.18; P = 0.006). Daily weight gain was similar in the zinc (18.2 ± 5.6 g · kg⁻¹ · d⁻¹) and control (17.0 ± 8.7 g · kg⁻¹ · d⁻¹) groups (P = 0.478).

CONCLUSION

Oral zinc supplementation given at high doses reduces morbidities and mortality in preterm neonates. This trial was registered in the Australian New Zealand Clinical Trial Register as ACTRN12612000823875.

Micronutrient fortification of food and its impact on woman and child health: a systematic review

BACKGROUND

Vitamins and minerals are essential for growth and metabolism. The World Health Organization estimates that more than 2 billion people are deficient in key vitamins and minerals. Groups most vulnerable to these micronutrient deficiencies are pregnant and lactating women and young children, given their increased demands. Food fortification is one of the strategies that has been used safely and effectively to prevent vitamin and mineral deficiencies.

METHODS

A comprehensive search was done to identify all available evidence for the impact of fortification interventions. Studies were included if food was fortified with a single, dual or multiple micronutrients and impact of fortification was analyzed on the health outcomes and relevant biochemical indicators of women and children. We performed a meta-analysis of outcomes using Review Manager Software version 5.1.

RESULTS

Our systematic review identified 201 studies that we reviewed for outcomes of relevance. Fortification for children showed significant impacts on increasing serum micronutrient concentrations. Hematologic markers also improved, including hemoglobin concentrations, which showed a significant rise when food was fortified with vitamin A, iron and multiple micronutrients. Fortification with zinc had no significant adverse impact on hemoglobin levels. Multiple micronutrient fortification showed non-significant impacts on height for age, weight for age and weight for height Z-scores, although they showed positive trends. The results for fortification in women showed that calcium and vitamin D fortification had significant impacts in the post-menopausal age group. Iron fortification led to a significant increase in serum ferritin and hemoglobin levels in women of reproductive age and pregnant women. Folate fortification significantly reduced the incidence of congenital abnormalities like neural tube defects without increasing the incidence of twinning. The number of studies pooled for zinc and multiple micronutrients for women were few, though the evidence suggested benefit. There was a dearth of evidence for the impact of fortification strategies on morbidity and mortality outcomes in women and children.

CONCLUSION

Fortification is potentially an effective strategy but evidence from the developing world is scarce. Programs need to assess the direct impact of fortification on morbidity and mortality.

Selected macro/micronutrient needs of the routine preterm infant

Requirements for optimal nutrition, especially for micronutrients, are not well defined for premature infants. The "reference fetus," developed by Ziegler et al,(1) has served as a model to define nutritional needs and studies designed to determine nutrient requirements. Revision of nutrient requirements and provision of optimal nutrition may lead to improved outcomes in preterm infants. Appropriate provision of nutrients also may help prevent nutritional disorders, such as metabolic bone disease and anemia. In this review, we discuss calcium, phosphorus, magnesium, vitamin D, iron, and copper, and define optimal intakes based on the available published data.

Longitudinal study on trace mineral compositions (selenium, zinc, copper, manganese) in Korean human preterm milk

We measured selenium, zinc, copper and manganese concentrations in the human milk of Korean mothers who gave birth to preterm infants, and compared these measurements with the recommended daily intakes. The samples of human milk were collected postpartum at week-1, -2, -4, -6, -8, and -12, from 67 mothers who gave birth to preterm infants (< 34 weeks, or birth weight < 1.8 kg). All samples were analyzed using atomic absorption spectrophotometry. The concentrations of selenium were 11.8 ± 0.5, 11.4 ± 0.8, 12.7 ± 0.9, 11.4 ± 0.8, 10.8 ± 0.9, and 10.5 ± 1.3 µg/L, zinc were 7.8 ± 0.5, 9.1 ± 0.8, 7.2 ± 0.9, 8.0 ± 0.8, 7.4 ± 0.9, and 6.6 ± 1.2 mg/L, copper were 506 ± 23.6, 489 ± 29.4, 384 ± 33.6, 356 ± 32.9, 303 ± 35.0, and 301 ± 48.0 µg/L and manganese were 133 ± 4.0, 127 ± 6.0, 125 ± 6.0, 123 ± 6.0, 127 ± 6.0, and 108 ± 9.0 µg/L at week-1, -2, -4, -6, -8, and -12, respectively. The concentrations of selenium and zinc meet the daily requirements but that of copper is low and of manganese exceeds daily requirements recommended by the American Academy of Pediatrics, Committee on Nutrition.

Neonatal zinc supplementation for prevention of mortality and morbidity in breastfed low birth weight infants: systematic review of randomized controlled trials

OBJECTIVES

To evaluate whether zinc supplements prevent mortality and morbidity in breastfed low birth weight infants.

METHODS

All randomized or qausi-randomized trials with individual or cluster allocation and using concurrent controls were included. Study population included LBW infants irrespective of gestational status who were exclusively or predominantly breastfed at the initiation of intervention. Intervention comprised zinc salts given as tablets or syrups orally to provide at least 1 RDA of elemental zinc for at least a period of 14 days, introduced within one month of birth. Electronic databases were searched irrespective of language and publication status.

FINDINGS

Three trials from developing countries met the inclusion criteria. Limited data did not indicate a reduced risk of mortality (1 trial, RR=1.11; 95% CI 0.57 to 2.18 at one year), hospitalization rate (1 trial, odds ratio 1.10; 95% CI 0.87 to 1.39), acute respiratory infection (1 trial), or diarrhea (2 trials). However, the trial reporting on mortality was not adequately powered for evaluating this outcome. There was no evidence of an increase in weight (3 trials) or height (2 trials) at either 6 months or one year of age, or of an increased risk of vomiting following zinc supplementation. Serum zinc levels at the end of intervention were significantly higher in the supplemented group (2 trials).

CONCLUSIONS

In view of no convincing evidence of benefits from the limited data available, currently there is no justification for recommending routine zinc supplementation for breastfed LBW newborns in developing countries.

Trace elements and antioxidant enzymes in extremely low birthweight infants

Oxygen radicals are believed to contribute to typical diseases of prematurity, such as bronchopulmonary dysplasia (BPD), intraventricular haemorrhage (IVH), retinopathy of prematurity (ROP) and necrotising enterocolitis (NEC). Our aim was to investigate whether these disorders are associated with disturbances in antioxidant enzyme activities and with low trace elements, which are co-factors of antioxidant enzymes. 209 infants with birthweight less than 1000g were enrolled into a European multicentre randomised erythropoietin (rhEPO) trial; 155 developed one or more of the above mentioned diseases. We analysed Zn, Cu, Fe, Se in plasma and red blood cells (RBCs), superoxide dismutase (CuZn-SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in RBCs on the 3rd and 68th day of life. Zn, Fe, Se in plasma, and Se in RBCs decreased (p<0.01), and Zn in RBC (p<0.001), CuZn-SOD (p<0.01) and CAT increased (p<0.05), whereas GSH-Px remained unchanged. No differences were observed between the rhEPO and control groups. Antioxidant enzyme activities did not correlate with gestational age. In infants with BPD, IVH, ROP, or NEC, CuZn-SOD and CAT (p<0.05) were higher at day 68 than in infants without these diseases. CuZn-SOD and GSH-Px at 3 days and CuZn-SOD at 68 days correlated positively (p<0.05) with the duration of oxygen treatment. In conclusion, in ELBW infants, trace element concentrations decreased over the first 10 weeks of life. Lower trace element concentrations, did not affect the activities of CuZn-SOD, GSH-Px, and CAT. Typical diseases of prematurity were not associated with decreased antioxidant enzyme activities.

Growth in high risk infants <1500 g birthweight during the first 5 weeks

BACKGROUND

Growth of very low birthweight (VLBW) infants is used to monitor nutrition and intrauterine velocity is taken as the desired goal.

AIM

We hypothesised that beside nutrition growth failure is caused by disease severity.

METHODS

Prospective longitudinal study of 45 VLBW infants undergoing intensive care, mechanical ventilation was used as proxy to disease severity. Nutritional intake, body weight, length, head circumference, and lower leg length (LLL) were measured during the first 5 weeks of life.

RESULTS

Birthweight and gestational age were lower in 22 ventilated than in 23 unventilated infants (p<0.01). Median daily intake was 3.2 and 2.8 g/kg for protein (n.s.), 108 and 112 kcal/kg for energy (n.s.), 175 and 160 ml/kg for volume (p<0.01) up to day 35, respectively. Chronic lung disease occurred in 12 infants, five of whom were treated with dexamethasone. Artificial ventilation (p<0.01) and dexamethasone treatment (p<0.05) were independent predictors of weight gain. Median weight gain (8.2 and 9.7 g/kg/d), head growth (0.45 and 0.60 cm/week), and LLL growth (0.28 and 0.35 mm/d) were lower (p<0.05) in ventilated than in non-ventilated infants, respectively. The correlation of LLL growth with body length (r=0.31, p<0.05) and head growth (r=0.42, p<0.01) was weak. Dexamethasone arrested growth; median LLL gain was 0.21 and 0.31 mm/d in ventilated infants with and without dexamethasone (p<0.05).

CONCLUSION

In VLBW infants, fetal growth rates are not reached with current feeding practice. In addition to inadequate nutrition, factors directly related to disease and treatment contribute to postnatal growth failure.

Selenium status in term and preterm infants during the first months of life

OBJECTIVE

We hypothesized that very low birth weight (VLBW) infants have reduced serum and red blood cell (RBC) selenium (Se) at birth, which decrease further with current nutrition and are associated with chronic lung disease and septicaemia.

DESIGN

We studied Se intake, concentration in serum and RBCs and glutathione peroxidase (GSH-Px) activity in preterm and term infants from birth until 16 weeks. Data are mean+/-standard deviation (s.d.).

SETTING

Seventy-two preterm infants in two groups, born in Berlin, gestational age 26+0/30+0 weeks, birth weight 845/1270 g, with low Se intake (2.2+/-0.8/2.5+/-1.2 microg/kg/day), and 55 term infants, gestational age 39+1 weeks, birth weight 3160 g, born in Venezuela (high Se intake: 29+/-8 microg/day).

RESULTS

A balance study in 10 preterm infants showed that Se is well absorbed from human milk (77+/-9%). Serum concentration was higher in term (142.0+/-40.0 microg/l) than in preterm infants (17.8+/-8.1/19.9+/-2.2 microg/l) at 4/7 weeks. Serum and RBC concentration of Se declined in all infants, low values in preterm infants did not correlate with chronic lung disease and septicaemia. GSH-Px activity in RBCs remained stable until 6 weeks of age in all infants and was not correlated with Se in RBCs.

CONCLUSIONS

Se concentration in serum decreases during the first weeks of life and depends on intake. GSH-Px activity is not useful as a marker for Se status in infants up to 16 weeks after birth.