Background

There is increasing evidence that poor growth of preterm infants is a risk factor for poor long-term development, while the effects of early postnatal growth restriction are not well known. We utilized a rat model to examine the consequences of different patterns of postnatal growth and hypothesized that early growth failure leads to impaired development and insulin resistance. Rat pups were separated at birth into normal (N, n = 10) or restricted intake (R, n = 16) litters. At d11, R pups were re-randomized into litters of 6 (R-6), 10 (R-10) or 16 (R-16) pups/dam. N pups remained in litters of 10 pups/dam (N-10). Memory and learning were examined through T-maze test. Insulin sensitivity was measured by i.p. insulin tolerance test and glucose tolerance test.

Results

By d10, N pups weighed 20% more than R pups (p < 0.001). By d15, the R-6 group caught up to the N-10 group in weight, the R-10 group showed partial catch-up growth and the R-16 group showed no catch-up growth. All R groups showed poorer scores in developmental testing when compared with the N-10 group during T-Maze test (p < 0.05). Although R-16 were more insulin sensitive than R-6 and R-10, all R groups were more glucose tolerant than N-10.

Conclusion

In rats, differences in postnatal growth restriction leads to changes in development and in insulin sensitivity. These results may contribute to better elucidating the causes of poor developmental outcomes in human preterm infants.

There is very little data regarding trace mineral nutrition in infants with small intestinal ostomies. Here we evaluated 14 infants with jejunal or ileal ostomies to measure their zinc absorption and retention and biochemical zinc and copper status. Zinc absorption was measured using a dual-tracer stable isotope technique at two different time points when possible. The first study was conducted when the subject was receiving maximal tolerated feeds enterally while the ostomy remained in place. A second study was performed as soon as feasible after full feeds were achieved after intestinal repair. We found biochemical evidence of deficiencies of both zinc and copper in infants with small intestinal ostomies at both time points. Fractional zinc absorption with an ostomy in place was 10.9% ± 5.3%. After reanastamosis, fractional zinc absorption was 9.4% ± 5.7%. Net zinc balance was negative prior to reanastamosis. In conclusion, our data demonstrate that infants with a jejunostomy or ileostomy are at high risk for zinc and copper deficiency before and after intestinal reanastamosis. Additional supplementation, especially of zinc, should be considered during this time period.

Background

Zinc and copper are essential for preterm infants, but recommended requirements from different groups vary widely. Recommended zinc intakes have steadily increased over the years. Although this would be expected to impair copper absorption, recommended copper intakes have not risen in parallel.

Objectives

To systematically review the literature on zinc and copper retention in preterm infants; to examine the effect on zinc intake on copper retention; and to estimate the zinc and copper intakes required to meet the levels of zinc and copper retention required for normal growth.

Design

Studies reporting zinc and/or copper retention in preterm infants (<36 weeks of gestation) during the first 120 days of life were identified using PubMed. Only studies reporting net retention were included.

Results

Fourteen studies on zinc retention reporting data on 45 different groups were identified. Eleven studies (32 groups) were identified reporting copper retention. Zinc retention was significantly higher at higher zinc intakes, and higher in formula-based diets than in human milk based diets. Zinc intakes of between 1.8-2.4 mg/kg/d (from formula based diets) and 2.3-2.4 mg/kg/d (from human-milk based diets) were required to achieve adequate zinc retention. Copper retention was significantly positively correlated with copper intake and significantly negatively correlated with zinc intake. At the zinc intakes suggested previously (1.8-2.4, 2.3-2.4 mg/kg/d), copper intakes of between 200 and 250 mcg/kg/d are required to ensure adequate copper retention.

Conclusions

Our results support the higher zinc intakes recommended in recent guidelines. However, they suggest that recommended copper intakes have not kept pace with increasing zinc intakes, and that preterm infants may need higher copper intakes than currently recommended.

Background & aims

Preterm infants are a heterogeneous group and many accumulate growth deficits before and after initial hospital discharge. Although this is associated with worse cognitive outcome, recent meta-analyses suggest that nutrient fortification of breast milk, or the use of nutrient and energy rich formulae after discharge exert little effect on growth and neurodevelopment. However, the complexity of study design, inclusion criteria and outcome parameters, combined with differences in formula composition mean that meta-analysis may overlook important effects of differing interventions in sub-groups.

Methods

We systematically identified evidence and mapped the information on Participants, Intervention, Comparator, and Outcome (PICO) from 31 published studies illustrating the marked heterogeneity in study design and interventions next to outcomes on (quality of) growth and neurodevelopment.

Results

Despite significant heterogeneity in study design, we found that nutrient enriched diets after discharge show no negative effects but frequently improve growth parameters at some point in the course of the study, in particular for boys. The data indicates that when energy requirements are adequate, increased protein results in increased growth and lean mass (LM) accretion; In particular, higher protein to energy ratios lead to increased lean mass accretion, and increased head circumference (HC) at one year. However, improvements in neurodevelopmental outcome were rarely seen.

Conclusion

This comprehensive evidence mapping approach to the field provides a broad but detailed overview of the currently available evidence. Furthermore, we identified key gaps in existing knowledge on the role of nutrient enrichment in the post-discharge period.

Background

Postnatal growth restriction is common in preterm infants and is associated with long-term neurodevelopmental impairment. Recent trends in postnatal growth restriction are unclear.

Methods

Birth and discharge weights from 25,899 Californian very low birthweight infants (birth weight 500-1500 g, gestational age 22-32 weeks) who were born between 2005 and 2012 were converted to age-specific Z-scores and analysed using multivariable modelling.

Results

Birthweight Z-score did not change between 2005 and 2012. However, the adjusted discharge weight Z-score increased significantly by 0.168 Z-scores (0.154, 0.182) over the study period, and the adjusted fall in weight Z-score between birth and discharge decreased significantly between those dates (by 0.016 Z-scores/year). The proportion of infants who were discharged home below the 10th weight-for-age centile or had a fall in weight Z-score between birth and discharge of >1 decreased significantly over time. The comorbidities most associated with poorer postnatal growth were medical or surgical necrotising enterocolitis, isolated gastrointestinal perforation and severe retinopathy of prematurity, which were associated with an adjusted mean reduction in discharge weight Z-score of 0.24, 0.57, 0.46 and 0.32, respectively. Chronic lung disease was not a risk factor after accounting for length of stay.

Conclusions

Postnatal, but not prenatal, growth improved among very low birthweight infants between 2005 and 2012. Neonatal morbidities including necrotising enterocolitis, gastrointestinal perforations and severe retinopathy of prematurity have significant negative effects on postnatal growth.

Introduction

Prenatal and early postnatal growth are known to be abnormal in patients with CHD. Although adult metabolic risk is associated with growth later in childhood, little is known of childhood growth in CHD.

Patients and methods

Retrospective data were collected on 551 patients with coarctation of the aorta, hypoplastic left heart syndrome, single ventricle physiology, tetralogy of Fallot, transposition of the great arteries, or ventricular septal defects. Weight, height, and body mass index data were converted to Z-scores. Body size at 2 years and growth between 2 and 20 years, 2 and 7 years, and 8 and 15 years were compared with Normative data using a sequential series of mixed-effects linear models.

Results

A total of 4660 weight, 2989 height, and 2988 body mass index measurements were analysed. Body size at 2 years of age was affected by cardiac diagnosis and gender. Abnormal growth was frequent and varied depending on cardiac diagnosis, gender, and the time period considered. The most abnormal patterns were seen in patients with tetralogy of Fallot, hypoplastic left heart syndrome, or single ventricle physiology. Potentially high-risk growth, a combination of small body size at 2 years and rapid subsequent growth, was seen in several groups.

Conclusions

Childhood and adolescent growth patterns were gender- and lesion-specific. Several lesions were associated with abnormal patterns of childhood growth known to be associated with an increased risk of adult adiposity or metabolic risk in other populations. Further information is needed on the long-term metabolic risks of survivors of CHD.