Strategies for feeding the preterm infant

Role of parenteral lipid emulsions in the preterm infant

Parenteral nutrition (PN) is necessary for infants unable to receive adequate calories enterally due to prematurity, decreased bowel length, or functional intestinal disorders. While PN can be life saving, its use is associated with significant risks of sepsis from catheter-associated infections and progressive liver dysfunction from prolonged use. The preterm infant population is at highest risk for these complications due to the presence of multiple comorbidities and immaturity of the biliary system. Strong data has implicated parenteral lipids in the multifactorial pathogenesis of PN-associated liver disease (PNALD). However, lipids are essential in early infant development, particularly in the neurocognitive development of preterm infants. Substitution of the lipid source from soybean oil to fish oil has emerged as a safe and efficacious treatment of PNALD, with marked improvements in morbidity and mortality. Knowledge of the developmental needs and physiologic limitations of preterm infants is crucial to optimizing parenteral lipid administration to nurture growth, and minimize and treat associated complications. The purpose of this review is to provide an overview of lipid requirements of the preterm infant and discuss the role of parenteral lipid emulsions in the management of PNALD and other diseases of prematurity.

Continuous milk feeding versus intermittent bolus feeding in preterm infants

We aimed to assess the current knowledge on continuous versus intermittent bolus feeding in preterm infants. We found that existing evidence does not support the firm recommendation of one strategy among the many alternatives. However, although many areas remain to be investigated, it is probable that continuous feeding might be advantageous compared to intermittent feeding in favoring the faster establishment of full enteral feeding, and decreasing the risk of hypoxic-ischemic gut damage in preterm neonates in critical condition, especially SGA infants, by limiting their gastrointestinal oxygen requirement.

Nutritional assessment in neonatal and prepubertal children with a history of extrauterine growth restriction

BACKGROUND

Nutritional deficit during perinatal stage may induce significant alterations in adipose tissue and increase the risk of obesity, metabolic syndrome and cardiovascular disease in children with a history of extrauterine growth restriction (EUGR).

AIMS

To describe the nutritional status in neonatal and prepubertal with a history of EUGR and establish an association between EUGR and later conditions.

STUDY DESIGN

Descriptive, analytical, observational case-control study.

SUBJECTS

The study included a sample of 38 prepubertal children with a history of EUGR, and 123 gender-and-age matched controls.

OUTCOME MEASURES

The EUGR group was asked to answer a food frequency questionnaire. Analysis of body composition in both groups included anthropometric measurements, assessment of blood pressure and biochemical markers.

RESULTS

Newborns with EUGR received parenteral feeding with a standard nutritional regime and long-chain fatty acid support for 41 ± 23 days; enteral feeding with a special formula for premature infants was initiated at 7 ± 11 days of life. At the prepubertal stage, daily fiber and fatty acid intake in children who had experienced EUGR in the neonatal stage was below the recommended intake. In the EUGR group, the intake of vegetables, fruits and olive oil was below dietary recommendations, while the intake of butchery, fatty meats, pastries and snacks was above the recommendations for the Spanish population.

CONCLUSIONS

Appropriate nutrition education strategies should be developed for children with a history of EUGR to prevent later associated pathologies, as neonatal nutritional support and feeding during childhood are associated with an increase in diseases in this risk group.

Very early feeding in stable small for gestational age preterm infants: a randomized clinical trial

OBJECTIVE

To examine the effect of initiating very early feeding on time-to-reach full feeding in stable, small for gestational age (SGA) preterm infants.

METHOD

Preterm infants with gestational age below 37 weeks and birth weight below the 10(th) percentile were randomly allocated to a very early (within 24 hours of birth) feeding regimen or delayed (after 24 hours of birth) feeding. All infants had in utero evidence of absent or reverse diastolic flow. Infants unable to start early feeding were excluded. Time-to-reach full feeding, feeding progression, and related morbidity were compared. Electrogastrography (EGG) was used to measure pre- and postprandial gastric motility on the second and seventh day after feeding initiation.

RESULTS

Sixty infants were included in the study, 30 in each group. Infants included in the very early feeding regimen achieved full enteral feeding sooner than controls (98±80-157 vs. 172±123-261 hours of age, respectively; p= 0.004) and were discharged home earlier (p=0.04). No necrotizing enterocolitis (NEC) was documented in both study groups. Gastric motility was improved at day seven after feeding initiation in both study groups, with no difference between groups.

CONCLUSIONS

Stable SGA preterm infants on a very early feeding regimen achieved full enteral feeding and were discharged home significantly earlier than those on a delayed regimen, with no excess morbidity.

Near-infrared spectroscopy measurements of splanchnic tissue oxygenation during continuous versus intermittent feeding method in preterm infants

OBJECTIVES

The aim of the present study was to compare the effects of continuous and intermittent bolus milk feeding on splanchnic regional oxygenation (rSO₂S) in small-for-gestational age (SGA) and appropriate-for-gestational age (AGA) preterm infants.

METHODS

Infants with gestational age <32 weeks were prospectively studied by near-infrared spectroscopy. Each infant was given a milk bolus in ~10 minutes (intermittent feeding) followed after 3 hours by a 3-hour continuous feeding. rO₂S and splanchnic fractional oxygen extraction ratio (FOES [S = splanchnic]) were recorded 30 minutes before (T₀) and 30 minutes after the beginning of bolus feeding (T₁), 30 minutes before (T₂), at the end (T₃), and 30 minutes after the continuous feeding period (T₄).

RESULTS

rSO2S increased at T₁ in both AGA and SGA groups, whereas FOES did not vary during the study period. Moreover, we found that rSO2S was higher and FOES was lower at T₁ and T₃ in the AGA than in the SGA group.

CONCLUSIONS

Bolus milk feeding increases splanchnic oxygenation in both AGA and SGA infants, whereas continuous feeding does not. Splanchnic oxygenation is higher in AGA than in SGA infants both during bolus and continuous feeding. Continuous enteral feeding could help to limit the risk of hypoxic-ischemic gut damage in preterm infants in critical condition, especially in AGA infants.

How to administrate erythropoietin, intravenous or subcutaneous?

AIM

To determine whether adding recombinant erythropoietin to the intravenous (IV) solution and administering it as a 24-h continuous infusion would result in an erythropoietic effect not inferior to that seen with subcutaneous (SC) administration.

METHODS

Infants weighing ≤1500 grams and ≤32 weeks of gestational age were randomly assigned at 72 h of life to receive erythropoietin (300 units/kg, 3 times a week until 36 complete weeks of postmenstrual age or discharge), either subcutaneously [erythropoietin subcutaneous (ESC) group] or added to IV fluids [erythropoietin intravenous (EIV) group].

RESULTS

One hundred infants were randomized (50 in the EIV group and 50 in the ESC group). The incidence of transfusions was comparable in the two groups, similar in baseline characteristics and haematologic values at study entry. Phlebotomy losses did not differ between groups, and at the end of the study, there were no differences in reticulocyte counts, transferrin saturation and ferritin. No differences in the incidence of side effects were observed.

CONCLUSIONS

In preterm infants, continuous intravenous administration of erythropoietin was not inferior to SC dosing.

Delayed introduction of progressive enteral feeds to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

The introduction of enteral feeds for very preterm (< 32 weeks) or very low birth weight (< 1500 g) infants is often delayed for several days or longer after birth due to concern that early introduction may not be tolerated and may increase the risk of necrotising enterocolitis (NEC). However, delaying enteral feeding could diminish the functional adaptation of the gastrointestinal tract and prolong the need for parenteral nutrition with its attendant infectious and metabolic risks.

OBJECTIVES

To determine the effect of delayed introduction of progressive enteral feeds on the incidence of necrotising enterocolitis, mortality and other morbidities in very preterm or very low birth weight infants.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2013, Issue 3), MEDLINE (1966 to April 2013), EMBASE (1980 to April 2013), CINAHL (1982 to April 2013), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that assessed the effect of delayed (more than four days after birth) versus earlier introduction of progressive enteral feeds on the incidence of NEC, mortality and other morbidities in very preterm or very low birth weight infants.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two review authors.

MAIN RESULTS

We identified seven randomised controlled trials in which a total of 964 infants participated. Few participants were extremely preterm (< 28 weeks) or extremely low birth weight (< 1000 g). The trials defined delayed introduction as later than five to seven days after birth and early introduction as less than four days after birth. Meta-analyses did not detect statistically significant effects on the risk of NEC (typical risk ratio (RR) 0.92 (95% confidence interval (CI) 0.64 to 1.34) or all-cause mortality (typical RR 1.26 (95% CI 0.78 to 2.01)). Three of the trials restricted participation to growth-restricted infants with Doppler ultrasound evidence of abnormal fetal circulatory distribution or flow. Planned subgroup analyses of these trials did not find any statistically significant effects on the risk of NEC or all-cause mortality. Infants who had delayed introduction of enteral feeds took longer to establish full enteral feeding (reported median difference two to four days).

AUTHORS' CONCLUSIONS

The evidence available from randomised controlled trials suggests that delaying the introduction of progressive enteral feeds beyond four days after birth does not affect the risk of developing NEC in very preterm or very low birth weight infants, including growth-restricted infants. Delaying the introduction of progressive enteral feeds results in a few days delay in establishing full enteral feeds but the clinical importance of this effect is unclear. The applicability of these findings to extremely preterm or extremely low birth weight is uncertain. Further randomised controlled trials in this population may be warranted.

The enigma to achieve normal postnatal growth in preterm infants--using parenteral or enteral nutrition?

AIM

To evaluate whether increasing the amount of amino acids and energy in parenteral nutrition combined with rapid increment of enteral feeding improves postnatal growth in preterm infants.

METHODS

Observational study; two consecutive year-cohorts of preterm infants; Cohort 2 received higher supplementation of parenteral amino acids and energy with more rapid enhancement of enteral feeding than Cohort 1. Nutritional intake, weight and head circumference (HC) were compared.

RESULTS

Cohort 2 [N: 79, gestational age (GA): 29.8 ± 2.2 weeks, birth weight (BW): 1248 ± 371 g] achieved full enteral feeds earlier (p < 0.001) and had a higher protein/energy intake during the first week (p < 0.001) than Cohort 1 (N: 68, GA: 29.5 ± 2.3 weeks, BW: 1261 ± 339 g). Both cohorts developed cumulative protein/energy deficits, but less in Cohort 2 (p < 0.01). Appropriate for gestational age infants (AGA) of Cohort 2 improved weight gain until week 5 (p < 0.01) compared to AGA of Cohort 1, nevertheless all infants demonstrated a decline in mean standard deviation score (>1) for weight at term. Small for GA infants failed to improve HC.

CONCLUSION

Improved parenteral intake may lead to improved short-term postnatal weight gain. Faster increase of enteral nutrition was well tolerated but failed to prevent nutritional deficits. Practising early enteral feeding with higher supplementation of nutrients may be needed and requires further study.

A phase II randomized clinical trial on cerebral near-infrared spectroscopy plus a treatment guideline versus treatment as usual for extremely preterm infants during the first three days of life (SafeBoosC): study protocol for a randomized controlled trial

Background

Every year in Europe about 25,000 infants are born extremely preterm. These infants have a 20% mortality rate, and 25% of survivors have severe long-term cerebral impairment. Preventative measures are key to reduce mortality and morbidity in an extremely preterm population. The primary objective of the SafeBoosC phase II trial is to examine if it is possible to stabilize the cerebral oxygenation of extremely preterm infants during the first 72 hours of life through the application of cerebral near-infrared spectroscopy (NIRS) oximetry and implementation of an clinical treatment guideline based on intervention thresholds of cerebral regional tissue saturation rStO₂.

Methods/Design

SafeBoosC is a randomized, blinded, multinational, phase II clinical trial. The inclusion criteria are: neonates born more than 12 weeks preterm; decision to conduct full life support; parental informed consent; and possibility to place the cerebral NIRS oximeter within 3 hours after birth. The infants will be randomized into one of two groups. Both groups will have a cerebral oximeter monitoring device placed within three hours of birth. In the experimental group, the cerebral oxygenation reading will supplement the standard treatment using a predefined treatment guideline. In the control group, the cerebral oxygenation reading will not be visible and the infant will be treated according to the local standards. The primary outcome is the multiplication of the duration and magnitude of rStO₂ values outside the target ranges of 55% to 85%, that is, the ‘burden of hypoxia and hyperoxia’ expressed in ‘%hours’. To detect a 50% difference between the experimental and control group in %hours, 166 infants in total must be randomized. Secondary outcomes are mortality at term date, cerebral ultrasound score, and interburst intervals on an amplitude-integrated electroencephalogram at 64 hours of life and explorative outcomes include neurodevelopmental outcome at 2 years corrected age, magnetic resonance imaging at term, blood biomarkers at 6 and 64 hours after birth, and adverse events.

Discussion

Cerebral oximetry guided interventions have the potential to improve neurodevelopmental outcome in extremely preterm infants. It is a logical first step to test if it is possible to reduce the burden of hypoxia and hyperoxia.

Trial registration

ClinicalTrial.gov, NCT01590316

Bacteriological, biochemical, and immunological modifications in human colostrum after Holder pasteurisation

OBJECTIVE

The objective of this work was to evaluate the effect of Holder pasteurisation of human colostrum on a variety of microbiological, biochemical, and immunological parameters.

METHODS

Colostrum samples from 10 donors, and 8 samples of mature milk used as controls, were heated at 62.5°C for 30 minutes. Bacterial counts and the concentration of furosine, lactose, myoinositol, glucose, lactulose, cytokines, and immunoglobulins were determined before and after the heat treatment.

RESULTS

Mean bacterial counts in nonpasteurised colostrum samples oscillated between 2.72 and 4.13 log10 colony-forming units per millilitre in the agar media tested. Holder pasteurisation led to the destruction of the bacteria originally present in the samples. Furosine was detected in all samples before pasteurisation and increased significantly after the heat treatment (from 6.60 to 20.59 mg/100 g protein). Lactulose content was below the detection limit in nonpasteurised colostrum, but it was detected in all samples and quantified in 7 of them (from 10.68 to 38.02 mg/L) after Holder pasteurisation. Lactose, glucose, and myoinositol concentrations did not change after Holder pasteurisation. The concentrations of most cytokines and immunoglobulins were significantly higher in colostrum than in mature milk samples. Immunoglobulin content, both in colostrum and in milk samples, was reduced during pasteurisation, whereas, among cytokines, only macrophage inflammatory protein-1β, interleukin-7, and granulocyte-macrophage-colony-stimulating factor concentrations were affected by this heat treatment.

CONCLUSIONS

Lactulose and furosine content could be used as heat treatment indicators in colostrum samples. Holder pasteurisation modified the immunological profile of both colostrum and mature milk.

Very low birth weight preterm infants are at risk for hypoglycemia once on total enteral nutrition

OBJECTIVE

To determine the occurrence of hypoglycemic episodes in very low birth weight preterm infants under total enteral nutrition and identify potential risk factors.

METHODS

In this single centre cohort study, we analyzed the patients' charts of preterm infants with a gestational age <32 weeks (n = 98). Infants were analyzed in two groups (group 1: birth weight <1000 g, n = 54; group 2: birth weight 1000-1499 g, n = 44). A total of 3640 pre-feeding blood glucose measurements were screened. Risk factors for the development of hypoglycemia were identified by linear and multiple logistic regression analyses.

RESULTS

In group 1, 44% (24 of 54) of infants experienced at least one asymptomatic episode of blood glucose <45 mg/dl (<2.5 mmol/l) as compared with 23% (10 of 44) in group 2. Regression analysis identified low gestational age and high carbohydrate intake as potential risk factors for the development of hypoglycemia.

CONCLUSIONS

Our results indicate that numerous preterm infants experience hypoglycemic episodes once on total enteral nutrition, especially those who are <1000 g at birth and those with a higher carbohydrate intake. Further studies evaluating a possible impact of these common although asymptomatic episodes on later development could help to better define thresholds that should be considered as "hypoglycemia" in this population.

Nutrition and bronchopulmonary dysplasia

We aimed to assess the current knowledge on the nutritional management of preterm infants at risk of developing bronchopulmonary dysplasia (BPD) or with BPD. We considered the evidence supporting the actual fluid and energy intake, proteins, lipids, and electrolytes requirement, and need for other nutrients in preterm infant at risk of developing BPD or with BPD. We concluded that, although many areas remain to be investigated, early nutrition support and careful adjustment of parenteral nutrition and appropriate enteral feeding selection may enhance the growth and contribute a better neurodevelopment in these patients.

Feeding intolerance in preterm infants fed with powdered or liquid formula: a randomized controlled, double-blind, pilot study

Feeding intolerance (FI) is usually defined as "gastric residual volume of more than 50 % of the previous feeding volume, emesis, abdominal distension or both of these symptoms and a decrease, delay or discontinuation of enteral feedings." We aimed to compare the incidence of FI in preterm infants fed with powdered or liquid infant formula, and in a prospective, double-blind, pilot study, 78 preterm infants were randomized to receive powdered or liquid form of the same preterm infant formula. The primary outcomes were the incidence of FI in both groups. The pH of gastric fluids was measured in the fasting and postprandial periods on the seventh day of life, and gastrointestinal complications were recorded during the hospitalization period. The incidence of FI was significantly higher in infants fed with liquid formula (n = 34) when compared with infants fed with powdered formula (n = 44) [9 (26.5 %) vs 2 (4.5 %), p < 0.01, respectively]. The median fasting gastric fluid pH was significantly lower and postprandial gastric fluid pH was significantly higher than in infants fed with powdered formula (2.9 vs 3.4, p < 0.01 and 6.0 vs 5.9, p < 0.05 respectively). Infants fed with liquid formula regained birth weight significantly later than infants fed with powdered formula (9.5 vs 8.0 days, p < 0.01).

CONCLUSION

Although the exact mechanisms are not clear, increased incidence of FI and delayed growth in the first weeks of life in preterm infants fed with liquid formula might be caused by altered gastric acidity or possible disrupted protein bioavailability due to different production and sterilization processes.

Evaluation of adequacy of protein and energy

Growth assessment is the most common measure of nutritional adequacy in pediatrics, especially when evaluating nutrition of preterm neonates. The American Academy of Pediatrics defines postnatal nutrient intake to promote growth as one that "approximates the rate of growth...for a normal fetus of the same post-menstrual age." It is known that in the fetus, fat and lean body mass are accreted progressively as gestation progresses, whereas postnatal growth and observed accretion of fat and lean body mass differ. This review discusses anthropometric measures used to assess growth, biochemical markers used to monitor nutritional sufficiency, and the effect of growth trajectory in preterm infants on health outcomes later in life.

Nutritional requirements and feeding recommendations for small for gestational age infants

We define the small for gestational age (SGA) infant as an infant born ≥ 35 weeks' gestation and <10th percentile on the Fenton Growth Chart. Policy statements from many organizations recommend mother's own milk for SGA infants because it meets most of their nutritional requirements and provides short- and long-term benefits. Several distinct patterns of intrauterine growth restriction are identified among the heterogeneous grouping of SGA infants; each varies with regard to neonatal morbidities, requirements for neonatal management, postnatal growth velocities, neurodevelopmental progress, and adult health outcomes. There is much we do not know about nutritional management of the SGA infant. We need to identify and define: infants who have "true" growth restriction and are at high risk for adverse metabolic outcomes in later life; optimal growth velocity and "catch-up" growth rates that are conducive with life-long health and well being; global approaches to management of hypoglycemia; and an optimal model for postdischarge care. Large, rigorously conducted trials are required to determine whether aggressive feeding of SGA infants results in improved nutritional rehabilitation, growth, and neurodevelopmental outcomes. Before birth, maternal supplementation with specific nutrients reduces the rate and severity of growth restriction and may prevent nutrient deficiency states if infants are born SGA. After birth, the generally accepted goal is to provide enough nutrients to achieve postnatal growth similar to that of a normal fetus. In addition, we recommend SGA infants be allowed to "room in" with their mothers to promote breastfeeding, mother-infant attachment, and skin-to-skin contact to assist with thermoregulation.

Sudden death from cardiac tamponade in an extremely low birth weight neonate with an umbilical venous catheter in situ

Pericardial effusion and cardiac tamponade are known to be rare but potentially fatal complications of umbilical venous catheterisation, even when the line tip is appropriately placed and is proximal to the right atrium.

We report a fatal case of cardiac tamponade due to the presence of pericardial total parenteral nutrition associated with bilateral pleural effusions in an extremely low birth weight neonate with an umbilical venous catheter.

It is important to promptly identify and treat this rare but devastating complication of what is often considered “routine” care. Timely pericardiocentesis should be considered in a preterm baby who deteriorates suddenly and has a central venous catheter

A historic cohort study on accelerated advancement of enteral feeding volumes in very premature infants

BACKGROUND

The optimal rate of enteral feeding (EF) advancement in very low birth weight infants is under debate.

OBJECTIVES

To evaluate the effects of accelerated EF advancement on the time to full enteral feeds, on early postnatal growth as well as on the frequency of necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP) in very premature infants.

METHODS

In a retrospective single-center historic cohort study, infants with a gestational age <32 weeks at birth and birth weight <1,500 g, born between January 1, 2006, and December 31, 2007 (n = 136), were compared with infants born between January 1, 2010, and December 31, 2010 (n = 88). In 2006/2007, enteral feeds were initiated on day 1 with 10-15 ml/kg/day and advanced by 15-20 ml/kg/day. In 2010, enteral feeds were initiated with 20 ml/kg/day on day 1 and advanced by 25-30 ml/kg/day. Full enteral feeds were defined as ≥ 140 ml/kg/day. Data are presented as median (P25-P75).

RESULTS

The time to establish full enteral feeds was shorter in 2010: 8 (7-11) days in 2006/2007 versus 6 (5-9) days in 2010. The incidences of NEC and FIP were 2.7 and 4.1% in 2006/2007 and 3.3 and 2.2% in 2010, respectively. Weight gain was not affected by the rate of EF advancement. Higher parenteral protein intake during week 1 in 2006/2007 was associated with better head circumference growth.

CONCLUSIONS

The new approach was associated with a significantly shorter period to establish full enteral feeds. No difference in the incidence of FIP or NEC was observed; however, the study was underpowered to detect small but possibly important differences.

Parenteral amino acid intakes: possible influences of higher intakes on growth and bone status in preterm infants

OBJECTIVE

To study the possible influences of amino acid (AA) intakes on growth and bone status in preterms.

STUDY DESIGN

Newborns, weighing <1250 g, received standard (S) or higher (H) parenteral AA intakes (3 or 4 g kg(-1) per day). Anthropometry, biochemistry and quantitative ultrasound (metacarpus bone transmission time (mcBTT), in μs) were measured prospectively.

RESULT

A total of 55 patients in group S and 60 in group H were studied. Significantly better growth rate was found in the H group during the study without signs of intolerance. We found a significant decrease in mcBTT from birth to 21 days in the H group; nonetheless, mcBTT at 36 weeks of gestational age significantly positively correlated with early AA and energy intakes. A significant positive correlation between mcBTT and lower limb length (LLL) at 21 days was found.

CONCLUSION

Early higher AA intakes improved growth without short-term AA intolerance. Nutritional parameters could influence bone growth. LLL was the anthropometric parameter that best correlated to bone status.

Treatment of necrotizing enterocolitis: an American Pediatric Surgical Association Outcomes and Clinical Trials Committee systematic review

OBJECTIVE

The optimal treatment of necrotizing enterocolitis (NEC) is a common challenge for pediatric surgeons. Although many studies have evaluated prevention and medical therapy for NEC, few guidelines for surgical care exist. The aim of this systematic review is to review and evaluate the currently available evidence for the surgical care of patients with NEC.

METHODS

Data were compiled from a search of PubMed, OVID, the Cochrane Library database, and Web of Science from January 1985 until December 2011. Publications were screened, and their references were hand-searched to identify additional studies. Clinicaltrials.gov was also searched to identify ongoing or unpublished trials. The American Pediatric Surgical Association Outcomes and Clinical Trials Committee proposed six questions deemed pertinent to the surgical treatment of NEC. Recent Cochrane Reviews examined three of these topics; a literature review was performed to address the additional three specific questions.

RESULTS

The Cochrane Reviews support the use of prophylactic probiotics in preterm infants less than 2500 grams to reduce the incidence of NEC, as well as the use of human breast milk rather than formula when possible. There is no clear evidence to support delayed initiation or slow advancement of feeds. For surgical treatment of NEC with perforation, there is no clear support of peritoneal drainage versus laparotomy. Similarly, there is a lack of evidence comparing enterostomy versus primary anastomosis after resection at laparotomy. There are little data to determine the length of treatment with antibiotics to prevent recurrence of NEC.

CONCLUSION

Based on available evidence, probiotics are advised to decrease the incidence of NEC, and human milk should be used when possible. The other reviewed questions are clinically relevant, but there is a lack of evidence-based data to support definitive recommendations. These areas of NEC treatment would benefit from future investigation.

Effectiveness of four manual breast pumps for mothers after preterm delivery in a developing country

BACKGROUND

Hospital-grade electric pumps may be useful to initiate and sustain adequate milk production for mothers who are unable to breast-feed their babies hospitalized at special care nurseries (SCN), but their cost is generally not affordable for SCN and for most mothers in developing countries. Therefore, manual breast pumps (MBPs) can be an alternative, but the best option is unknown considering clinical parameters and mothers' preference from among currently available MBPs.

OBJECTIVE

To compare the effectiveness of four MBPs in terms of milk volume, nutritional composition, and breast emptying in order to assist in making a choice for health care personnel and mothers in SCN settings. Duration of expression and maternal preference were also evaluated as secondary outcomes.

METHODS

Mothers of preterm infants used 4 MBPs in a random order, 2 with a squeeze-handle mechanism (Isis and Harmony) and 2 with a cylindrical mechanism (Little Heart and Evenflo), both at the hospital and in home settings using each pump over one 24-hour period.

RESULTS

Milk volume, nutritional composition, breast emptying, and duration of expression were not different among MBPs. Scale of maternal preference rated higher those with the squeeze-handle mechanism than the cylindrical mechanism (p < 0.05).

CONCLUSIONS

There was no difference found in the effectiveness across the four pumps tested. The mothers' rating for comfort and ease of use showed a marked difference between pumps. These factors, plus cost, need to be considered when evaluating manual pumps for use in SCN settings in developing countries.

Changes in perinatal care and predictors of in-hospital mortality for very low birth weight preterm infants

OBJECTIVE

Mortality of very low birth weight premature infants is of great public health concern. To better guide local intervention program, it is essential that current and reliable statistics be collected to understand the factors associated with mortality of these infants.

METHODS

Data of very low birth weight premature infants admitted to a neonatal unit during 2002-2009 was retrospectively collected. Changes in perinatal care between two halves of the study period (2002-2005 and 2006-2009) were identified. Factors associated with in-hospital mortality were found by logistic regression and a predictive score model was established.

FINDINGS

A total of 475 cases were enrolled. In-hospital mortality decreased from 29.8% in 2002-2005 to 28.1% in 2006-2009 (P>0.05). More infants born <28 gestational weeks survived to discharge in the latter epoch (38.1% vs 8.3%, P<0.05). Persistent pulmonary hypertension of newborn, pulmonary hemorrhage, birth weight <000 grams, gestational age <33 weeks, feeding before 3 postnatal days and enteral feeding were found predictors of in-hospital mortality by logistic regression. The discriminating ability of the predictive model was 82.4% and the cutoff point was -0.56.

CONCLUSION

Survival of very low birth weight premature neonates was not significantly improved in 2006-2009 than 2002-2005. Infants with a score higher than -0.56 were assessed to be at high risk of in-hospital mortality. Multi-center studies of planned follow-up are needed to develop a comprehensive and applicable score system.

Impact of oxidative stress in fetal programming

Intrauterine stress induces increased risk of adult disease through fetal programming mechanisms. Oxidative stress can be generated by several conditions, such as, prenatal hypoxia, maternal under- and overnutrition, and excessive glucocorticoid exposure. The role of oxidant molecules as signaling factors in fetal programming via epigenetic mechanisms is discussed. By linking oxidative stress with dysregulation of specific target genes, we may be able to develop therapeutic strategies that protect against organ dysfunction in the programmed offspring.

Continuous parenteral and enteral nutrition induces metabolic dysfunction in neonatal pigs

BACKGROUND

We previously showed that parenteral nutrition (PN) compared with formula feeding results in hepatic insulin resistance and steatosis in neonatal pigs. The current aim was to test whether the route of feeding (intravenous [IV] vs enteral) rather than other feeding modalities (diet, pattern) had contributed to the outcome.

METHODS

Neonatal pigs were fed enterally or parenterally for 14 days with 1 of 4 feeding modalities as follows: (1) enteral polymeric formula intermittently (FORM), (2) enteral elemental diet (ED) intermittently (IEN), (3) enteral ED continuously (CEN), and (4) parenteral ED continuously (PN). Subgroups of pigs underwent IV glucose tolerance tests (IVGTT) and hyperinsulinemic-euglycemic clamps (CLAMP). Following CLAMP, pigs were euthanized and tissues collected for further analysis.

RESULTS

Insulin secretion during IVGTT was significantly higher and glucose infusion rates during CLAMP were lower in CEN and PN than in FORM and IEN. Endogenous glucose production rate was suppressed to zero in all groups during CLAMP. In the fed state, plasma glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide (GLP)-1, and GLP-2 were different between feeding modalities. Insulin receptor phosphorylation in liver and muscle was decreased in IEN, CEN, and PN compared with FORM. Liver weight was highest in PN. Steatosis and myeloperoxidase (MPO) activity tended to be highest in PN and CEN. Enterally fed groups had higher plasma GLP-2 and jejunum weight compared with PN.

CONCLUSIONS

PN and enteral nutrition (EN) when given continuously as an elemental diet reduces insulin sensitivity and the secretion of key gut incretins. The intermittent vs continuous pattern of EN produced the optimal effect on metabolic function.

Body composition in newborn infants: 5-year experience in an Italian neonatal intensive care unit

The aim of nutrition in neonatology is to achieve a healthy growth that mimics, both in terms of growth rates and quality of growth, that of a normal fetus of the same gestational age. In addition, providing an optimal amount and quality of nutrients significantly contributes to the attainment of a neurodevelopment similar to that of an infant born at term. Yet, a high risk of developing metabolic syndrome in relation to aggressive nutrition and accelerated postnatal growth velocity has been reported in former preterm infants. Considering the strict interrelationship that exists between early nutrition, growth, and subsequent health, the development of body composition in early infancy, in terms of fat mass, may contribute to the long-term "programming" process. Hence, accurate and non-invasive measurement of infant body composition, which evaluates the quality in addition to the amount of weight gain, represents a useful tool for gaining further insight into the relationship between birth weight or time in utero and future development. Preterm infants, including those born small for gestational age, have been reported to develop an increased and/or aberrant adiposity, in addition to postnatal growth retardation, when assessed at term-corrected age. However, within the first 5 months, preterm infants, either born adequate or small for gestational age, show a recovery of fat mass, and attain fat mass values comparable to those of full-term infants assessed at birth. The metabolic consequences of these findings on the long-term health need to be further clarified.

Early lipid supply and neurological development at one year in very low birth weight (VLBW) preterm infants

BACKGROUND

The rapid growth of the developing brain during early post-natal life makes it particularly vulnerable to a nutritional deficit. The neurological development of the very low birth weight preterm infant could be related to early lipid supply.

AIMS

To evaluate in preterm infants of gestational age ≤ 28 weeks of amenorrhea (WA) the relations between the neurological development determined at a corrected age of one year using the test of Brunet-Lézine and 1) the cumulative intakes of proteins, carbohydrates, lipids and energy during the first 28 days of life and 2) the weight gain in the first 28 days of life.

MATERIALS AND METHODS

Study of a mono-centric cohort of 48 premature infants of gestational age ≤ 28 WA consecutively hospitalized and followed longitudinally up to a corrected age of one year.

RESULTS

In simple univariate analysis, there was a significant correlation between the developmental quotient (DQ) at a corrected age of one year and the cumulative intake of energy and lipids at 14 days of life (p=0.02, p=0.01, respectively), the number of days to reach the minimum weight (p=0.02) and the weight gain from birth to D28 of life (p=0.04). There was no correlation between the DQ and early intake of proteins or carbohydrates. In multivariate analysis, only the association between the DQ at one year of corrected age and the cumulative lipid intake at 14 days of life remained statistically significant (p=0.04).

CONCLUSION

Our study demonstrates the importance of early lipid supply during the first two weeks of life for the neurological development at a corrected age of one year of very low birth weight preterm infants.

Parenteral nutrition-associated cholestasis: an American Pediatric Surgical Association Outcomes and Clinical Trials Committee systematic review

OBJECTIVE

The aim of this study was to review evidence-based data addressing key clinical questions regarding parenteral nutrition-associated cholestasis (PNAC) and parenteral nutrition-associated liver disease (PNALD) in children.

DATA SOURCE

Data were obtained from PubMed, Medicine databases of the English literature (up to October 2010), and the Cochrane Database of Systematic Reviews.

STUDY SELECTION

The review of PNAC/PNALD has been divided into 4 areas to simplify one's understanding of the current knowledge regarding the pathogenesis and treatment of this disease: (1) nonnutrient risk factors associated with PNAC, (2) PNAC and lipid emulsions, (3) nutritional (nonlipid) considerations in the prevention of PNAC, and (4) supplemental medications in the prevention and treatment of PNAC.

RESULTS

The data for each topic area relevant to the clinical practice of pediatric surgery were reviewed, evaluated, graded, and summarized.

CONCLUSIONS

Although the conditions of PNAC and PNALD have been well recognized for more than 30 years, only a few concrete associations and treatment protocols have been established.

Fortification of maternal milk for preterm infants

During the last few decades, neonatal survival rates for preterm infants have markedly been improved. The American Academy of Pediatrics recommended that preterm neonates should receive sufficient nutrients to enable them to grow at a rate similar to that of fetuses of the same gestational age. Although human milk is the recommended nutritional source for newborn infants for at least the first six months of postnatal life, unfortified human breast milk may not meet the recommended nutritional needs of growing preterm infants. Human milk must therefore be supplemented (fortified) with the nutrients in short supply. The fortification of human milk can be implemented in two different forms: standard and individualized. The new concepts and recommendations for optimization of human milk fortification is the "individualized fortification". Actually, two methods have been proposed for individualization: the "targeted/tailored fortification" and the "adjustable fortification". In summary, the use of fortified human milk produces adequate growth in premature infants and satisfies the specific nutritional requirements of these infants. The use of individualized fortification is recommended.

Perioperative management of low birth weight infants for open-heart surgery

Infants of birth weight ≤2500 g are termed low birth weight (LBW). These children often have considerable morbidity from prematurity and intra-uterine growth restriction. Additionally, LBW infants have increased risk for cardiac and noncardiac congenital anomalies and may require surgery. Primary rather than palliative surgical repair of cardiac lesions has been preferred in recent years. However, LBW remains a risk factor for increased mortality and morbidity after open-heart surgery (OHS). There is a paucity of information about the anesthetic challenges presented by LBW infants undergoing OHS. This review summarizes the perioperative issues of relevance to anesthesiologists who manage these high-risk patients. Emphasis is placed on management concerns that are unique to LBW infants. Retrospective data from the authors' institution are provided for those aspects of anesthetic care that lack published studies. Successful outcome often requires substantial hospital resources and collaborative multi-disciplinary effort.

[Infusion therapy for neonates, infants and children]

Intravenous administration of fluids, electrolytes and glucose are the most common interventions in hospitalized pediatric patients. Parenteral fluid administration can be life-saving, however, if used incorrectly it also carries substantial risks. Perioperatively, adequate hydration, prevention of electrolyte imbalances and maintenance of normoglycemia are the main goals of parenteral fluid therapy. Conceptionally, the distinction between maintenance requirements, deficits and ongoing loss is helpful. Although the pathophysiological basis for parenteral fluid therapy was clarified in the first half of the 20th century, some aspects still remain controversial. In newborn infants, rational parenteral fluid therapy must take into account large insensible fluid losses, adaptive changes of renal function in the first days of life and the fact that neonates do not tolerate prolonged periods of fasting. In older infants the occurrence of iatrogenic hyponatremia with the use of hypotonic solutions has led to a critical reappraisal of the validity of the Holliday-Segar method for calculating maintenance fluid requirements in the postoperative period. Pragmatically, only isotonic solutions should be used in clinical situations which are known to be associated with increases in antidiuretic hormone (ADH) secretion. In this context, it is important to realize that in contrast to lactated Ringer's solution, the use of normal saline can lead to hyperchloremic acidosis in a dose-dependent fashion. Although there is no convincing evidence that colloids are better than crystalloids, there are clinical situations where the use of the more expensive colloids seems justified. It may be reasonable to choose a solution for fluid replacement which has a composition comparable to the composition of the fluid which must be replaced. Although hypertonic saline can reduce an elevated intracranial pressure, this therapy cannot be recommended as a routine procedure because there is currently no evidence that this intervention improves long-term outcome in pediatric patients with traumatic brain injury.

A fermented formula in pre-term infants: clinical tolerance, gut microbiota, down-regulation of faecal calprotectin and up-regulation of faecal secretory IgA

Intestinal bacterial colonisation in pre-term infants is delayed compared with full-term infants, leading to an increased risk of gastrointestinal disease. Modulation of colonisation through dietary supplementation with probiotics or prebiotics could decrease such a risk. The present study evaluated clinical tolerance, the effects on gut microbiota, and inflammatory and immunological mucosal responses to an infant formula adapted for pre-term infants that included in its manufacturing process a fermentation step with two probiotic strains, Bifidobacterium breve C50 and Streptococcus thermophilus 065, inactivated by heat at the end of the process. A total of fifty-eight infants (gestational age: 30–35 weeks), fed either the fermented pre-term formula or a standard pre-term formula, were followed up during their hospital stay. Clinical tolerance, faecal microbiota using a culture and a culture-independent method (temporal temperature gel electrophoresis), faecal calprotectin and secretory IgA were analysed weekly. No difference was observed regarding anthropometric data and digestive tolerance, except for abdominal distension, the incidence of which was lower in infants fed the fermented formula for 2 weeks. Bacterial colonisation was not modified by the type of feeding, particularly for bifidobacteria. Faecal calprotectin was significantly lower in infants fed the fermented formula for 2 weeks, and secretory IgA increased with both mother's milk and the fermented formula. The fermented formula was well tolerated and did not significantly modulate the bacterial colonisation but had benefits on inflammatory and immune markers, which might be related to some features of gastrointestinal tolerance.

Delayed introduction of progressive enteral feeds to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

The introduction of progressive enteral feeds for very low birth weight (VLBW) infants is often delayed for several days or longer after birth due to concern that earlier introduction may not be tolerated and may increase the risk of necrotising enterocolitis (NEC). However, delaying enteral feeding could diminish the functional adaptation of the gastrointestinal tract and prolong the need for parenteral nutrition with its attendant infectious and metabolic risks.

OBJECTIVES

To determine the effect of delayed introduction of progressive enteral feeds on the incidence of NEC, mortality and other morbidities in VLBW infants.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2010, Issue 4), MEDLINE (1966 to December 2010), EMBASE (1980 to December 2010), CINAHL (1982 to December 2010), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that assessed the effect of delayed (more than four days' postnatal age) versus earlier introduction of progressive enteral feeds on the incidence of NEC, mortality and other morbidities in VLBW infants.

DATA COLLECTION AND ANALYSIS

Data collection and analysis were performed in accordance with the standard methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

We identified five randomised controlled trials (RCT) in which a total of 600 infants participated. The trials defined delayed introduction as later than five to seven days after birth and early introduction as less than four days after birth. Two of the trials, in which a total of 488 infants participated, only recruited growth-restricted infants with Doppler ultrasound evidence of abnormal fetal circulatory distribution or flow. Meta-analyses did not detect statistically significant effects on the risk of NEC [typical relative risk 0.89, 95% confidence interval (CI) 0.58 to 1.37] or all cause mortality (typical relative risk 0.93, 95% CI 0.53 to 1.64). Infants who had delayed introduction of enteral feeds took significantly longer to establish full enteral feeding (reported median difference three days).

AUTHORS' CONCLUSIONS

Current trial data do not provide evidence that delayed introduction of progressive enteral feeds reduces the risk of NEC in VLBW infants. Delaying the introducing of progressive enteral feeds results in several days delay in establishing full enteral feeds but the clinical importance of this effect is unclear. Further RCTs are needed to give more precise estimates of the effect of delaying the introduction of enteral feeds on clinical outcomes in VLBW infants.

Companion animals symposium: development of the mammalian gastrointestinal tract, the resident microbiota, and the role of diet in early life

Mammalian gastrointestinal (GI) development is guided by genetic determinants established during the evolution of mammals and matched to the natural diet and environment. Coevolution of the host GI tract (GIT) and the resident bacteria has resulted in commensal relationships that are species and even individual specific. The interactions between the host and the GI bacteria are 2-way and of particular importance during the neonatal period, when the GIT needs to adapt rapidly to the external environment, begin processing of oral foods, and acquire the ability to differentiate between and react appropriately to colonizing commensal and potentially pathogenic bacteria. During this crucial period of life, the patterns of gene expression that determine GI structural and functional development are modulated by the bacteria colonizing the previously sterile GIT of fetuses. The types and amounts of dietary inputs after birth influence GI development, species composition, and metabolic characteristics of the resident bacteria, and the interactions that occur between the bacteria and the host. This review provides overviews of the age-related changes in GIT functions, the resident bacteria, and diet, and describes how interactions among these 3 factors influence the health and nutrition of neonates and can have lifelong consequences. Necrotizing enterocolitis is a common GI inflammatory disorder in preterm infants and is provided as an example of interactions that go awry. Other enteric diseases are common in all newborn mammals, and an understanding of the above interactions will enhance efforts to support neonatal health for infants and for farm and companion animals.

Early transient hypoglycemia is associated with increased albumin nitration in the preterm infant

BACKGROUND

The clinical significance of early transient hypoglycemia (ETH), a frequent event in preterm newborns, is a highly controversial issue. In experimental models, hypoglycemia has been reported to cause oxidative stress. Among the reactive species, early generated peroxynitrite is responsible for protein nitration and lipid peroxidation, a process referred to as nitrative stress.

OBJECTIVES

The aim of the present study is to investigate whether ETH is associated with protein nitration in the preterm newborn.

METHODS

Using a novel highly sensitive ELISA, we quantified plasma nitroalbumin (PNA) as a marker of peroxynitrite generation in 72 preterm newborns (28-36 weeks), among which 25 had a glycemia level of <2.5 mmol/l during the first hour of life (H1).

RESULTS

PNA was significantly higher in ETH than in normoglycemic infants at H1 [median = 6.3 (3.8-8.8) vs. 3.4 ng/ml (2.1-5.1), p = 0.027] and at day 1 [median = 6.6 (5.6-15.3) vs. 3.9 ng/ml (2.3-4.6), p = 0.014]. PNA was inversely correlated with glycemia at H1 (r = -0.30, p = 0.01) and at day 1 (r = -0.63, p = 0.001). In ETH infants, lactatemia was inversely correlated with PNA. At day 1, PNA was higher in ETH infants treated by gavage than in those treated with intravenous dextrose [median = 8.9 ng/ml (7.1-10.4) vs. 4.4 ng/ml (2.6-5.7), p = 0.008].

CONCLUSIONS

These results indicate that ETH is associated with increased peroxynitrite generation resulting in systemic protein nitration in premature newborns. Treatment of ETH with intravenous dextrose is associated with lower PNA levels than gavage.

Role of intestinal transporters in neonatal nutrition: carbohydrates, proteins, lipids, minerals, and vitamins

To support rapid growth and a high metabolic rate, infants require enormous amounts of nutrients. The small intestine must have the complete array of transporters that absorb the nutrients released from digested food. Failure of intestinal transporters to function properly often presents symptoms as "failure to thrive" because nutrients are not absorbed and as diarrhea because unabsorbed nutrients upset luminal osmolality or become substrates of intestinal bacteria. We enumerate the nutrients that constitute human milk and various infant milk formulas, explain their importance in neonatal nutrition, then describe for each nutrient the transporter(s) that absorbs it from the intestinal lumen into the enterocyte cytosol and from the cytosol to the portal blood. More than 100 membrane and cytosolic transporters are now thought to facilitate absorption of minerals and vitamins as well as products of digestion of the macronutrients carbohydrates, proteins, and lipids. We highlight research areas that should yield information needed to better understand the important role of these transporters during normal development.

Romantic attachment in young adults with very low birth weight - The Helsinki Study of Very Low Birth Weight Adults

Early attachment relationships from infancy onward contribute to attachment patterns later in life, to the ability to build up close relationships and to well-being in general. Severely preterm birth may challenge the development of these attachment relationships. We studied whether there are differences in attachment patterns related to romantic relationships between young adults (mean age 22.4 years, s.d. 2.2 years) with very low birth weight (VLBW, <1500 g; n = 162) and their peers born at term (n = 172), who completed the Experiences in Close Relationships Questionnaire - Revised. Young adults born at VLBW showed lower attachment-related anxiety than their peers born at term (mean difference -9.5%, 95% CI -16.0 to -2.6) when adjusted for sex, age, parental education and being in a romantic relationship currently. The groups did not differ in attachment-related avoidance. In subgroup analyses, the VLBW women born small for gestational age (SGA, birth weight <-2 s.d.) scored on average 14.8% (95% CI 3.1-26.6) higher than the control women on attachment avoidance. The effects remained after the exclusion of 18 participants with neurosensory deficits. We found no evidence for a compromised attachment pattern in young adults born at VLBW, with a possible exception of women born SGA at VLBW. VLBW adults were rather characterized by a lower level of attachment-related anxiety.

Fortification of maternal milk for very low birth weight (VLBW) pre-term neonates

Human milk is the best food for all neonates; however, in pre-term infants, especially those with a very low birth weight, it may lead to insufficient intake of protein and energy. The use of fortified human milk produces adequate growth in premature infants and satisfies the specific nutritional requirements of these babies. To improve the nutritional management of pre-term infants < or =35 weeks' gestational age, an individualised human milk fortification system based on the analysis of maternal milk was evaluated.

Parenteral and enteral feeding in preterm piglets differently affects extracellular matrix proteins, enterocyte proliferation and apoptosis in the small intestine

The preterm intestine is immature and responds differently to total parenteral nutrition (TPN) and enteral nutrition, compared with the term intestine. We hypothesised that in preterms, diet composition and feeding route affect mucosal morphology, enterocyte mitosis and apoptosis, and the distribution of laminin-1, fibronectin and collagen IV (extracellular matrix proteins (ECMP)). Preterm piglets (93·5 % of gestation) were delivered via caesarean section and birth weight-matched allocated to one of the four experimental groups: the piglets were either euthanised immediately after delivery, after 3 d of TPN or after 2 d enteral feeding with colostrum or milk formula, following 3 d of TPN. We combined immunohistochemistry, image analysis and stereological measurements to describe the intestinal mucosal layer. No significant changes occurred after 3 d of TPN. Feeding colostrum or milk replacer for 2 d after TPN was associated with an increased crypt depth. Only enteral feeding with colostrum resulted in an increased villus height and mitotic index. Neither TPN nor enteral feeding changed the distribution pattern of ECMP or the occurrence of bifid crypts. The immature distribution pattern of ECMP in TPN-fed piglets, coupled with unchanged enterocyte mitosis and apoptosis indices, illustrates that feeding preterm pigs 3 d TPN does not lead to mucosal atrophy. Despite the invariable distribution of ECMP, colostrum was associated with crypt hyperplasia resulting in an increased villus height. These data illustrate that some mechanisms regulating cell turnover are immature in preterms and may in part explain the abnormal gut responses to TPN and enteral feeding in prematurely born pigs.

Induced preterm birth in sheep: a suitable model for studying the developmental effects of moderately preterm birth

Our aim was to characterize an ovine model of preterm birth that allows analysis of the developmental effects of preterm birth in the absence of postnatal confounding factors. Preterm birth was induced at 131 days of gestation in 82 lambs; controls (n = 31) were born at term (145 days). Overall survival of preterm lambs was 60%; males had significantly lower survival than females (44% vs 76%); 94% of term lambs survived. Although the birth weight of preterm lambs was approximately 0.9 kg lower than in term lambs, the crown-to-rump and forelimb lengths were similar. At 9 weeks after term-equivalent age, there were no differences in body weight or dimensions between preterm and term lambs; when adjusted for body weight, the heart was 21% heavier in preterm than term lambs. We conclude that moderately preterm birth in sheep is characterized by a greater survival of female lambs than males and has significant effects on organ development.

Neonatal macrosomia is an independent risk factor for adult metabolic syndrome

BACKGROUND

Weight in infancy correlates with risk of type 2 diabetes, hypertension, and obesity in adulthood. Clinical observations have been confounded by obesity-prone genotypes and obesity-linked lifestyles.

OBJECTIVES

To define the effects of isolated neonatal macrosomia in isogenic animals, we compared macrosomic and control C57Bl6 mice co-fostered by healthy dams receiving standard laboratory feed.

METHODS

Naturally occurring neonatal macrosomia was identified by a gender-specific weanling weight above the 90th percentile for the colony. Macrosomic and control mice were phenotyped in adulthood by exercise wheel, tail cuff and intraperitoneal insulin or glucose challenge.

RESULTS

Compared to control males, adult males with a history of neonatal macrosomia had significantly increased body weight, reduced voluntary activity, insulin resistance, fasting hyperinsulinemia, and impaired glucose tolerance. In contrast, adult females with neonatal macrosomia had no significant alteration in body weight or endocrine phenotypes, but did have higher blood pressures and lower heart rates than control females. After these baseline studies, all mice were switched to a hypercaloric, high fat diet (5 kcal/g, 45% of energy as fat). Twenty weeks later, male mice had impaired glucose tolerance and insulin resistance, independent of their weanling weight classification. While on high fat feeds, macrosomic males maintained a significantly higher body weight than control males.

CONCLUSIONS

We conclude that (1) in our murine model, neonatal macrosomia is an independent risk factor of adult metabolic syndrome, and (2) neonatal macrosomia accentuates the sexually dimorphic predisposition of C57Bl6 male mice towards glucose intolerance and C57Bl6 female mice towards hypertension.

IUGR does not predispose to necrotizing enterocolitis or compromise postnatal intestinal adaptation in preterm pigs

IUGR and preterm birth are leading causes of neonatal morbidity. We tested the hypothesis that IUGR predisposes to gut maladaption and necrotizing enterocolitis (NEC) using preterm pigs as models for preterm infants. First, full-term normal birth weight (NW) and IUGR ( approximately 65% of NW) pigs were compared. IUGR reduced intestinal weight per length, proportion mucosa, villous area, and sucrase activity at 2 d after birth (p < 0.05) but did not change relative organ weights. Next, groups of preterm pigs were fed formula or colostrum, starting at birth or after 2-3 d of total parenteral nutrition (TPN). Neonatal mortality (not related to NEC) was increased in IUGR versus NW preterm pigs (28 vs 10%, p < 0.01). NEC incidence was similar between IUGR and NW but higher after formula than colostrum feeding (46 vs 12%, p < 0.01) and higher after TPN than without TPN (61 vs 34% for formula pigs, p < 0.01). After feeding, relative intestinal mass and length were higher in IUGR versus NW pigs (+25-80%, p < 0.05) while brush border enzyme activities were similar. An enhanced gut trophic response to enteral feeding may help to improve postnatal intestinal adaptation and NEC resistance in preterm IUGR newborns.

Initial nutritional management of the preterm infant

Postnatal nutrition has a large impact on long-term outcome of preterm infants. Evidence is accumulating showing even a relationship between nutrient supply in the first week of life and later cognitive development in extremely low birth weight infants. Since enteral nutrition is often not tolerated following birth, parenteral nutrition is necessary. Yet, optimal parenteral intakes of both energy and amino acids are not well established. Subsequently, many preterm infants fail to grow well, with long-term consequences. Early and high dose amino acid administration has been shown to be effective and safe in very low birth weight infants, but the effect of additional lipid administration needs to be defined.

Neonatal management and long-term sequelae

Intrauterine or fetal growth restriction is best defined by using customised birth weight percentiles based upon the growth potential for an individual infant. Growth restriction in utero may be classified as asymmetric or symmetric depending upon the duration of the process. Asymmetric growth restriction is caused by placental insufficiency, maternal hypertensive conditions, long-standing maternal diabetes, smoking, living at altitude or multiple gestation. Symmetric growth restriction may be due to congenital infections, chromosomal or other abnormalities, fetal alcohol syndrome, low socioeconomic status or be constitutional. The underlying cause of growth restriction often predicts the potential adverse effects on the foetus and newborn and later effects in childhood and adulthood. With placental insufficiency, there may be chronic or acute on chronic fetal hypoxia with birth asphyxia and hypothermia, neonatal hypoglycaemia, polycythaemia and coagulopathy. Management is directed at prevention or early treatment of these conditions. In contrast, symmetrically growth-restricted infants should be examined carefully to look for congenital infections and malformations that may need specific interventions. Infants with constitutional short stature generally do not need any specific management. Feeding of growth-restricted infants is important to overcome deficiencies incurred in utero. Most infants show catch-up growth although about 10% do not. Those with excessive catch-up growth may be at greatest risk of developing insulin resistance in adulthood leading to diabetes, obesity and heart disease. The so-called fetal origins of disease may actually have a postnatal onset related more to excessive weight gain in infancy. There is still controversy over the indications for growth hormone treatment in growth-restricted infants who remain of short stature in early childhood. Intrauterine growth restriction is also associated with a five- to seven-fold increased risk of cerebral palsy probably due to chronic placental insufficiency.