Feeding strategies for premature infants: randomized trial of gastrointestinal priming and tube-feeding method

Feeding the ill or preterm infant

Illness and immaturity often interfere with a neonate's ability to receive full enteral feedings during the first week of life. The goals of feeding in the NICU are to nourish the preterm infant for appropriate growth and development and to facilitate the earliest possible discharge from the NICU. Early, small-volume feedings, or trophic feedings, have been studied as a method for achieving these goals. The high-risk infant given such trophic feedings not only receives minimum enteral nutrition, but also attains earlier full nutritional feedings and, consequently, is discharged home earlier. Oro- or nasal-gastric gavage feedings are usually indicated for this group of infants because of their physiologic immaturity and the frequent presence of respiratory illness. Recent studies support the use of intermittent bolus feedings, which have long been used for the premature infant. Several authors have noted advantages to continuous infusions as well. Because the infant is unable to pace or refuse gavage feedings, the caretaker must determine the appropriate volume of each feeding. The optimal volume for initiation and advancement of trophic and nutritional feedings is still under investigation, but reports have demonstrated safe volumes for even the extremely premature infant.

Early introduction of oral feeding in preterm infants

OBJECTIVE

To determine whether transition from tube to all oral feeding can be accelerated by the early introduction of oral feeding in preterm infants. It is hypothesized that this shortened transition time will lead to earlier attainment of all oral feeding.

DESIGN

Twenty-nine infants (<30 weeks' gestation) were randomized to an intervention or control group. The intervention group (n = 13) was initiated to oral feeding 48 hours after achieving full tube feeding (120 kcal/kg/d), and the feeding progression followed a structured protocol. The oral feeding management of the control infants (n = 16) was left to the discretion of their attending physicians. Oral feeding progress was monitored for achievement of selected feeding milestones: achievement of first and all successful oral feedings. Feeding performance was assessed by overall transfer (percent volume transferred during a feeding/total volume offered) and rate of milk transfer (mL/min), which were measured from introduction of oral feeding to first successful oral feeding.

RESULTS

Infants in the experimental group, when compared with their control counterparts, were introduced to oral feeding significantly earlier (31.1 +/- 1.3 vs 33.7 +/- 0.9 weeks' postmenstrual age, respectively) and attained all oral feeding significantly earlier as well (34.5 +/- 1.6 vs 36.0 +/- 1.5 weeks' postmenstrual age, respectively). The transition time from full tube feeding to all oral feeding was 26.8 +/- 12.3 days for the experimental group and 38.4 +/- 14.0 days for the control group. Both groups of infants demonstrated similar increase in overall transfer and rate of milk transfer from introduction of oral feeding until achievement of first successful oral feeding.

CONCLUSIONS

Early introduction of oral feeding accelerates the transition time from tube to all oral feeding. This not only allows earlier attainment of all oral feeding, but it also provides practice opportunities that enhance the oral motor skills necessary for safe and successful feeding.

Nutritional assessment and therapeutic interventions for the preterm infant

All components of assessment contribute to the final decision regarding nutritional status of the infant and the nutritional therapy indicated. One parameter by itself such as nutrient intake, weight change, or a laboratory value cannot clearly determine the total nutritional state of the infant. Achieving appropriate intakes and weight gains are two excellent parameters. Laboratory values can determine if nutrition is tolerated and manipulations are indicated.

Effect of enteral administration of insulin on intestinal development and feeding tolerance in preterm infants: a pilot study

OBJECTIVE

To determine in a pilot study whether enteral administration of insulin to preterm infants (26-29 weeks of gestational age) would enhance gastrointestinal development and reduce feed intolerance without adverse effects.

DESIGN

Eight preterm infants were given 4 U/kg/day insulin enterally from 4 to 28 days of age. Lactase activity was measured at 28 days of age, while measures of feed intolerance were made throughout the hospital stay. The results were compared with those of a matched historical cohort of 80 preterm infants.

SETTING

Tertiary care, university affiliated hospital.

MAIN OUTCOME MEASURES

Lactase activity and feed intolerance.

RESULTS

No adverse effects, such as hypoglycaemia, were observed after administration of insulin. The infants who received insulin had higher lactase activity and less feed intolerance than the controls (30% shorter time to full enteral feeds; fewer gastric residuals per infant).

CONCLUSION

These preliminary data suggest that enteral insulin administration may be of benefit in reducing feed intolerance in preterm infants. A randomised, blinded trial is warranted.

Evidence-based feeding guidelines for very low-birth-weight infants

Clinical practice guidelines (CPG) for the nutritional management of premature infants are limited. This project focused on the development of a research-based enteral feeding CPG for infants of < 1,500 g. The CPG was based on an extensive literature review and developed through a process of consensus decision making by a team of clinical researchers. Infants that weigh < 1,000 g initiate minimal enteral nutrition (MEN) at 48 hours; nutritional feedings begin on day 5 to 6 of life. For infants between 1,000 and 1,500 g, nutritional feedings begin at 48 hours and are advanced at a rate of less than 30 mL/kg per day. The benefits and risks of continuous versus intermittent nasogastric tube feeding were inconclusive; therefore, the CPG does not stipulate a feeding method. Breast milk is used preferentially, and specific guidelines for the definition and management of feeding intolerance are provided. A follow-up study testing this CPG has been completed and is published in the original research section of this issue.

Position of the American Dietetic Association: breaking the barriers to breastfeeding

It is the position of the American Dietetic Association (ADA) that broad-based efforts are needed to break the barriers to breastfeeding initiation and duration. Exclusive breastfeeding for 6 months and breastfeeding with complementary foods for at least 12 months is the ideal feeding pattern for infants. Increases in initiation and duration are needed to realize the health, nutritional, immunological, psychological, economical, and environmental benefits of breastfeeding. Breastfeeding initiation rates have increased, but cultural barriers to breastfeeding, especially against breastfeeding for 6 months and longer, still exist. Gaps in rates of breastfeeding based on age, race, and socioeconomic status remain. Children benefit from the biologically unique properties of human milk including protection from illness with resulting economic benefits. Mother's benefits include reduced rates of premenopausal breast and ovarian cancers. Appropriate lactation management is a critical component of successful breastfeeding for healthy women. Lactation support and management is even more important in women and children with special needs caused by physical or developmental disability, disease, or limited resources. Dietetics professionals have a responsibility to support breastfeeding through appropriate education and training, advocacy, and legislative action; through collaboration with other professional groups; and through research to eliminate the barriers to breastfeeding.

Feeding methods for the preterm infant

As more very immature preterm infants survive, provision of enteral feedings has become a major focus of concern. Although many aspects of gastrointestinal function are immature in the preterm infant, the ability of the preterm neonate to process and absorb enteral nutrients appears to be adequate enough to sustain nutritional needs. Few prospective randomized trials have compared the efficacy of different feeding methods. However, some studies have compared differing routes of feeding, rates of feeding, and volume of feeding. The ability to successfully digest enteral feedings may be inhibited or enhanced by pharmacological agents. The need to modify a feeding strategy can be monitored by tracking several measurements prospectively. Finally, there is a need to assess ongoing dietary needs of preterm infants for discharge planning.

Early aggressive nutrition in preterm infants

Increasingly, neonatologists are realizing that current feeding practices for preterm infants are insufficient to produce reasonable rates of growth, and earlier and larger quantities of both parenteral and enteral feeding should be provided to these infants. Unfortunately, there is very little outcome data to recommend any particular nutritional strategy to achieve better growth. Instead, the rationale for feeding regimens in many nurseries has been quite variably extrapolated from animal data and human studies conducted in gestationally more mature and/or stable neonates. Additionally, there are no well-controlled, prospective studies that validate any nutritional regimen for the very preterm and or sick, unstable neonate. The goal of this review is to present available data to help define the risks and benefits of early parenteral and enteral nutrition, particularly in very preterm neonates, concluding with a more aggressive approach to feeding these infants than has been customary practice.

Measuring intramucosal pH in very low birth weight infants

Maintenance of adequate perfusion is essential for health of the intestinal mucosa. Methods available to assess intestinal perfusion provide information on mesenteric blood flow, which may differ from mucosal flow. Intramucosal pH (pH(i)) is influenced by tissue oxygenation and perfusion. Gastric pH(i) can be measured using the technique of tonometry. A prospective observational clinical study was performed to examine relationships between measured gastric pH(i) and mucosal CO(2) (mCO(2)), and acid-base balance, gastrointestinal complications (necrotizing enterocolitis and perforation), and death in infants <1500 g birth weight. A nasogastric tonometry catheter (size 5F) was inserted into the stomach of infants, and pH(i) was calculated from mCO(2) levels measured using saline tonometry. Measurements were performed at 3, 12, 24, and 48 h, then daily until arterial access was unavailable. Two hundred eleven sets of measurements were performed on 38 infants [birth weight (mean +/-SD), 863 +/- 241 g; gestation, 26.5 +/- 1.8 wk; and median Clinical Risk Index for Babies score, 8.0 (interquartile range, 5.0-10.75)]. Mean pH(i) was 7.27 (95% confidence interval, 7.26-7.28) and mean mCO(2) was 47.0 mm Hg (95% confidence interval, 45.7-48.3 mm Hg). pH(i) and mCO(2) correlated significantly with arterial pH (pH(a)), arterial PCO(2) (PaCO(2)), and arterial base excess. There were no significant relationships between pH(a) and pH gap (pH(a)-pH(i)) or CO(2) gap (mCO(2)-PaCO(2)). Recurrent low pH(i) (<7.2 on more than one occasion) and an mCO(2)/PaCO(2) ratio of > or =1.29 were significantly associated with an increase in gastrointestinal complications. There were no statistically significant associations with death. In conclusion, changes in pH gap and CO(2) gap can occur without alteration in pH(a). Abnormalities in pH(i) might predict gastrointestinal complications in infants <1500 g.

Effects of age, feeding regimen, and glucocorticoids on catecholamine and cortisol excretion in preterm infants

BACKGROUND

The sympathoadrenal system is important in maintaining normal physiologic functioning in infants and increased output also can reflect stress. We sought to determine the effects of age, feeding regimen, and glucocorticoids on catecholamine and cortisol excretion in preterm infants and to assess whether a particular strategy of feeding enhanced sympathoadrenal development or was stressful.

METHODS

Preterm infants (26-30 wk gestation; n = 171) were assigned randomly to begin trophic feedings from day 4 through 14 (trophic group) or to start feedings at day 15 (standard group) with feedings administered either by bolus every 3 hours (bolus) or continuously over 24 hours (continuous). At 10, 28, 40, 50, and 60 days of age, urine was collected continuously for 6 hours for measurement of catecholamines (norepinephrine, epinephrine, dopamine), cortisol, and creatinine. Data were available for 98 infants.

RESULTS

Norepinephrine excretion increased with postnatal age. The increase with age was significantly greater in the trophic group compared with that in the standard group. Epinephrine excretion did not change with age, and there were no differences between trophic and standard groups. Dopamine excretion increased with age but was similar between trophic and standard groups (borderline significantly greater in the trophic group). Cortisol excretion increased with age and also was similar between trophic and standard groups. There was no effect on catecholamine or cortisol excretion of bolus vs continuous feedings, antenatal or postnatal corticosteroids, gestational age at birth, age at which full feedings were attained, or use of human milk compared with preterm formula.

CONCLUSIONS

The greatest determinant of catecholamine and cortisol excretion is postnatal age. Feeding method, type of feeding, and glucocorticoid administration in the amounts customarily used have little significant effect on catecholamine or cortisol excretion. The apparent link between early feeding and norepinephrine (and possibly dopamine) excretion warrants further investigation.

Randomized, multicenter trial of two different formulas for very early enteral feeding advancement in extremely-low-birth-weight infants

BACKGROUND

In extremely-low-birth-weight (ELBW) infants, formula feeding is required if human milk is not available. The tolerance of a new 'high' lactose (55 g/L), low protein, low phosphate, hydrolyzed protein formula (HLF) for early enteral feeding advancement of ELBW infants was compared with that of a low lactose (1 g/L) hydrolyzed protein formula (LLF).

METHODS

In a randomized multicenter trial, 99 ELBW infants were fed according to a standardized protocol beginning at 48 hours of age with 12 ml/kg daily increments. Primary outcome was the cumulative milk feeding volume (CFV) from days 3 to 14. The authors hypothesized that feeding HLF as a supplement to human milk would increase the CFV at least by 20% in at least 60% of matched pairs compared with LLF. A secondary issue was to investigate whether human milk would increase the CFV compared with formula.

RESULTS

The CFV was 720 mL/kg (range, 0-962 mL/kg) with HLF and 613 mL/kg (range, 3-1,283 mL/kg) with LLF feeding. There was no 20% difference. On day 14, the median feeding volume was 103 mL/kg. The CFV was 533 mL/kg (range, 0-962 mL/kg) in infants who received less than 10% of human milk and 832 mL/kg (range, 74-1,283 mL/kg) in infants who received more than 10%. Necrotizing enterocolitis (Bell stage > or =2) occurred only with LLF feeding (n = 5; P < 0.05).

CONCLUSIONS

The study failed to find the hypothesized 20% advantage of the new HLF. The observed advantage of human milk supports the hypothesis that it should be the first diet in ELBW infants; however, this hypothesis still must be confirmed in a controlled, randomized trial.

New concepts in necrotizing enterocolitis

Necrotizing enterocolitis is an overwhelming gastrointestinal emergency that primarily afflicts premature infants born weighing less than 1500 g. Despite years of investigation, the etiology remains unclear, and accepted prevention and treatment strategies are lacking. Studies published over the last year have provided new insight into several aspects of this complex disease. In this review, novel information is presented on (1) the epidemiology; (2) methods of early diagnosis, such as abdominal magnetic resonance imaging; (3) the importance of risk factors, including assessment of feeding strategies and role of bacterial colonization; (4) the pathophysiology, highlighting experimental and clinical trials evaluating the role of inflammatory mediators and growth factors on the disease; (5) preventive strategies, such as anaerobic bacterial supplementation; and (6) surgical interventions, including peritoneal drainage. Understanding some of these important aspects of necrotizing enterocolitis may help improve the outlook of patients with this dreaded disease. Although the incidence of neonatal necrotizing enterocolitis (NEC) and the mortality stemming from this disease have not significantly improved over the last 30 years, there is exciting new information that may significantly improve the outlook of patients with this overwhelming intestinal emergency in the near future.

Trophic feeding of the preterm infant

Trophic feeding is the practice of feeding minute volumes of enteral feeds in order to stimulate the development of the immature gastrointestinal tract of the preterm infant This paper reviews the randomized controlled studies that have examined the physiological and clinical responses to trophic feeding of the preterm infant. Trophic feeding alters gastrointestinal disaccharidase activity, hormone release, blood flow, motility and microbial flora. Clinical benefits appear to include improved milk tolerance, greater postnatal growth, reduced systemic sepsis and shorter hospital stay. There is currently no evidence of any adverse effects following trophic feeding.

Secretion of trophic gut peptides is not different in bolus- and continuously fed piglets

In neonates, bolus feeding is associated with greater rates of intestinal growth than is continuous feeding. We tested whether the concentrations and secretion rates of trophic gut peptides are higher in bolus-fed than in continuously fed piglets. Five 21-d-old piglets were surgically implanted with gastric, arterial and portal catheters and a portal blood flow probe. At postnatal d 30 and 31, pigs received an equal amount of primed continuous or bolus feeding of a cow's milk formula in a randomized, crossover design. During a 6-h period, portal blood flow and arterial and portal concentrations of glucagon-like peptide-2 (GLP-2), peptide YY (PYY) and gastric inhibitory polypeptide (GIP) were measured. All hormone levels were significantly increased within 1 h of the start of the experiment, independent of the feeding modality. There were no differences between bolus and continuous feeding in either the arterial concentrations or secretion rates of GLP-2, PYY and GIP. In both treatment groups, the increases in the plasma concentrations of GLP-2 and GIP after feeding were substantially greater than those for PYY. We conclude that the production or circulating concentrations of GLP-2, PYY and GIP are not significantly different in bolus- and primed continuously fed piglets.

Enhanced-calorie formulas: considerations and options

The long-term developmental impact of nutrition on the preterm newborn has recently been shown to be of even greater importance than previously recognized. Very immature or ill infants are challenged by the need for a high caloric intake, but are unable to tolerate large fluid volumes. These patients may require enhanced-calorie formulas to achieve the desired growth goals. Formula enhancement has traditionally been performed by uniquely developed recipes of base formula concentration with the addition of powdered formula or single components such as medium-chain triglycerides oil, protein, or polycose. These mixtures have been largely unstudied for bioavailability, long-term outcomes, and tolerance. Deviation from recommended protein, fat, carbohydrate, mineral, and vitamin delivery limits may impair growth or lead to undesirable side effects. The practitioner must have an understanding of when and how to use an enhanced formula and the important monitoring and assessment needs of the patient receiving enhanced-calorie formula.

Gastroesophageal endoscopic findings and gastrointestinal symptoms in preterm neonates with and without perinatal indomethacin exposure

BACKGROUND

The aim of this study was to investigate whether perinatal indomethacin treatment has effects on the development of esophageal and gastric lesions in preterm infants and to evaluate other potential etiologic factors behind these lesions.

METHODS

Sixty-nine infants were born at less than 33 weeks' gestation. Forty-five of these infants underwent treatment with perinatal indomethacin (study group) and 24 did not (control group). All underwent upper gastrointestinal tract endoscopy and biopsy during the neonatal period. The correlation between gastrointestinal symptoms, abnormal endoscopic findings, and the factors correlating with the development of esophageal and gastric mucosal lesions was evaluated.

RESULTS

Abnormal endoscopic findings were equally common in the study group (77.8%) and in controls (83.3%). There was no dependence between gastrointestinal symptoms and endoscopic findings because only 15 infants (21.7%) were symptomatic before endoscopy. The interval between endoscopy and the last perinatal indomethacin dose correlated significantly with abnormal esophageal findings and gastric mucosal lesions. Shorter duration of enteral feeding before endoscopy correlated with greater risk of abnormal esophageal findings. Older gestational age and need of ventilator treatment at the time of endoscopy remained the risk factors associated with abnormal gastric findings.

CONCLUSIONS

Esophageal and gastric lesions diagnosed by endoscopy correlate poorly with the gastrointestinal symptoms of patients. Short duration of enteral feeding seems to be correlated with an increased risk of esophageal mucosal lesions, increasing gestational age and ventilator treatment with gastric mucosal lesions, and perinatal indomethacin with esophageal and gastric mucosal lesions in preterm infants. Ventilator-treated preterm infants not receiving enteral nutrition and patients with indomethacin exposure might benefit from ulcer prophylaxis.

Stability of filgrastim and epoetin alfa in a system designed for enteral administration in neonates

OBJECTIVE

To determine the stability of recombinant granulocyte colony-stimulating factor (rG-CSF, filgrastim) and recombinant erythropoietin (rEpo, epoetin alfa) in a solution designed for enteral administration in the neonatal intensive care unit.

DESIGN

Filgrastim and epoetin alfa were added to a solution with NaCl 0.9%, sodium acetate, potassium chloride, and human albumin in concentrations designed to mimic human amniotic fluid. Additionally, the solution was dripped through polyvinyl chloride feeding tubes to simulate feedings, and aliquots were collected before, during, and after priming of the tube. Other aliquots were either frozen immediately, stored at room temperature, or refrigerated for 0, 6, 12, 18, and 24 hours.

MAIN OUTCOME MEASURES

Filgrastim and epoetin alfa concentrations in the various aliquots were compared with the concentrations in the original solution.

RESULTS

Filgrastim and epoetin alfa concentrations were stable for at least 24 hours when refrigerated and for at least three weeks when frozen. At room temperature, filgrastim was stable for 18 hours and epoetin alfa for 24 hours. Filgrastim concentrations did not vary significantly before, during, or after priming of the feeding tube, whereas epoetin alfa concentrations decreased significantly unless the feeding tube was primed with 10 mL of solution.

CONCLUSIONS

Filgrastim and epoetin alfa were stable in our amniotic fluid-like solution. In this respect, our solution is suitable for enteral administration to patients in the neonatal intensive care unit.

Feeding tolerance in preterm infants: randomized trial of bolus and continuous feeding

OBJECTIVE

To test the hypothesis that continuous gastric infusion (CGI) is better tolerated than intermittent gastric bolus (IGB) in small very low birth weight (VLBW) infants.

DESIGN

Two-center, prospective, randomized, unmasked clinical trial.

PATIENTS

28 VLBW infants (birth weight <1250 g). A strict feeding protocol was followed.

INTERVENTION

Patients were randomized to IGB or CGI.

MAIN OUTCOME MEASURES

Time to reach full feeds (160 cc/kg/d)(by design and real), daily weight, caloric intake, residual gastric volume and type of feeding (formula vs. human milk vs. both).

RESULTS

Five infants failed to complete the study because of death (n = 4) or protocol violation (n = 1). The two groups did not differ by birth weight or gestational age; infants fed via IGB reached full feeds earlier (p = 0.03) and had less delay in reaching full feeds than infants fed via CGI.

CONCLUSION

Contrary to our hypothesis, gravity IGB is more effective than CGI in improving feeding tolerance in small VLBW infants.

Growth outcomes of very low-birth weight infants in the newborn intensive care unit

Advances in perinatal medicine will continue to improve our care and increase our understanding of the unique nutritional requirements of the VLBW infant and especially of the ELBW infant. Developments that permit neonatologists to meet those nutritional needs should improve the growth and well-being of VLBW infants. Longitudinal growth curves of hospitalized VLBW infants, such as the ones described in this article, should not be considered optimal and should be updated as ways safely to improve the growth of VLBW infants are identified.

Feeding tolerance in premature infants fed fortified human milk

BACKGROUND

To evaluate feeding tolerance in premature infants immediately after the addition of human milk fortifier (HMF) to their expressed human milk diet.

METHODS

Data on milk intake, feeding tolerance, and related assessments and growth milestones from a prospective study of feeding strategies in premature infants were analyzed. The database was searched for the first day HMF was added to the feeding of infants receiving human milk exclusively. The following assessments were tabulated for the 5 days before and the 5 days after the addition of HMF: milk intake, the number of episodes of abdominal distension, gastric residual volume (GRV) more than 2 ml/kg and more than 50% of the volume fed in the prior 3 hours. bile-stained gastric residual, emesis or regurgitation, blood in the stool, the number of abdominal radiographs, the number of episodes of apnea and bradycardia, changes in findings in the clinical examination, and the number of hours feeding was withheld. The time to achieve full tube feeding, complete oral feeding, and hospital discharge were recorded.

RESULTS

Seventy-six exclusively human milk-fed premature infants (birth weight, 1065+/-18 g; gestational age, 27+/-0.1 weeks; mean +/- SEM) who received HMF beginning 22+/-0.8 days of age were evaluated. There were significant increases in milk intake and in the number of episodes of GRV more than 2 ml/kg and emesis after the addition of HMF. There were no differences in the number of hours feeding was withheld or any other assessment after the addition of HMF. Infants with increases in GRV more than 2 ml/kg and/or emesis after the addition of HMF were not more likely to be delayed in the time to achieve full tube feeding, complete oral feeding, or hospital discharge than infants who did not experience these events.

CONCLUSION

These data suggest that, when all feeding and related assessments and the time to achieve important growth milestones are considered, the addition of HMF does not adversely affect the outcome of the premature infant.

Early versus delayed initiation of progressive enteral feedings for parenterally fed low birth weight or preterm infants

BACKGROUND

Enteral feedings in very-low-birth-weight or sick preterm infants are often delayed for several days or weeks after birth even though delayed enteral feeding could diminish the functional adaptation of the gastrointestinal tract and result in feeding intolerance later. Early initiation of feedings, if well-tolerated, may promote growth and shorten the duration of parenteral nutrition and hospital stay without increasing the risk for necrotizing enterocolitis (NEC).

OBJECTIVES

For parenterally fed low-birth-weight infants, to assess the effects of early enteral feedings initiated shortly after birth compared to delayed enteral feedings (with similar schedules for advancing feedings in each group).

SEARCH STRATEGY

Searches were performed of the Oxford Database of Perinatal Trials, the Cochrane Neonatal Review Group registry, MEDLINE, abstracts and conference proceedings, references from relevant publications in the English language, and studies identified by personal communication.

SELECTION CRITERIA

Only randomized or quasi-randomized clinical trials were considered. Trials were included if 1) they enrolled low birth weight or preterm infants who were all given parenteral nutrition; 2) the infants were randomly assigned to either early enteral feedings (mean or median age <=4 days) or late enteral feedings (>4 days) of formula or breast milk; 3) except when feeding intolerance developed, the feedings were progressively advanced starting within 72 hours after initiating feedings; and 4) the goals for total nutrient intake were similar for both groups. (We did not require the duration or total intake of parenteral nutrients to be similar for both groups because these variables may be affected by the age at which feedings are initiated.)

DATA COLLECTION AND ANALYSIS

The two reviewers reached consensus for inclusion of trials. Data regarding clinical outcomes were extracted and evaluated by two reviewers (JET and KAK) independently. Authors were contacted as needed and feasible to clarify or provide missing data. The specific data that were needed were requested in writing and by telephone.

MAIN RESULTS

Only two small studies were identified (one with 60 patients and one with 12 patients). Five randomized trials were excluded because parenteral nutrition was not provided or because the groups were assigned to receive different parenteral intakes as well as different enteral intakes. An additional unpublished small trial was excluded because both groups were fed "late" according to our categorization. Because there were no clinical outcomes which were reported in both of the included studies, no meta analysis of the results was performed. Based on the results of the individual studies, early feedings had no significant effect on weight gain, necrotizing enterocolitis, mortality, or age at discharge, although important effects cannot be excluded with the small number of patients studied. Some benefits of early feedings were noted in the larger trial (Davey) -- fewer days on parenteral nutrition, fewer infants who were treated with gastric suction and interruption of feedings, fewer infants with sepsis evaluations, and fewer infants with percutaneous central venous catheters.

REVIEWER'S CONCLUSIONS

The benefits and hazards of early and delayed feedings have received very little study in clinical trials, and the effects on major clinical outcomes, including necrotizing enterocolitis and death, remain uncertain. With the availability of parenteral nutrition in contemporary neonatal units, it is unclear whether high-risk infants should receive early or delayed feedings.

Feeding strategies for premature infants: beneficial outcomes of feeding fortified human milk versus preterm formula

BACKGROUND

In a large-scale study of feeding strategies in premature infants (early vs later initiation of enteral feeding, continuous vs bolus tube-feeding, and human milk vs formula), the feeding of human milk had more effect on the outcomes measured than any other strategy studied. Therefore, this report describes the growth, nutritional status, feeding tolerance, and health of participating premature infants who were fed fortified human milk (FHM) in comparison with those who were fed exclusively preterm formula (PF).

METHODS

Premature infants were assigned randomly in a balanced two-way design to early (gastrointestinal priming for 10 days) versus late initiation of feeding (total parenteral nutrition only) and continuous infusion versus intermittent bolus tube-feeding groups. The type of milk was determined by parental choice and infants to receive their mother's milk were randomized separately from those to receive formula. The duration of the study spanned the entire hospitalization of the infant. To evaluate human milk versus formula feeding, we compared outcomes of infants fed >50 mL. kg-1. day-1 of any human milk (averaged throughout the hospitalization) with those of infants fed exclusively PF. Growth, feeding tolerance, and health status were measured daily. Serum indices of nutritional status were measured serially, and 72-hour nutrient balance studies were conducted at 6 and 9 weeks postnatally.

RESULTS

A total of 108 infants were fed either >50 mL. kg-1. day-1 human milk (FHM, n = 62) or exclusively PF (n = 46). Gestational age (28 +/- 1 weeks each), birth weight (1.07 +/- 0.17 vs 1.04 +/- 0.19 kg), birth length and head circumference, and distribution among feeding strategies were similar between groups. Infants fed FHM were discharged earlier (73 +/- 19 vs 88 +/- 47 days) despite significantly slower rates of weight gain (22 +/- 7 vs 26 +/- 6 g. kg-1. day-1), length increment (0.8 +/- 0.3 vs 1.0 +/- 0.3 cm. week-1), and increment in the sum of five skinfold measurements (0.86 +/- 0.40 vs 1.23 +/- 0.42 mm. week-1) than infants fed PF. The incidence of necrotizing enterocolitis and late-onset sepsis was less in the FHM group. Overall, there were no differences in any measure of feeding tolerance between groups. Milk intakes of infants fed FHM were significantly greater than those fed PF (180 +/- 13 vs 157 +/- 10 mL. kg-1. day-1). The intakes of nitrogen and copper were higher and magnesium and zinc were lower in group FHM versus PF. Fat and energy absorption were lower and phosphorus, zinc, and copper absorption were higher in group FHM versus PF. The postnatal retention (balance) surpassed the intrauterine accretion rate of nitrogen, phosphorus, magnesium, zinc, and copper in the FHM group, and of nitrogen, magnesium, and copper in the PF group.

CONCLUSIONS

Although the study does not allow a comparison of FHM with unfortified human milk, the data suggest that the unique properties of human milk promote an improved host defense and gastrointestinal function compared with the feeding of formula. The benefits of improved health (less sepsis and necrotizing enterocolitis) associated with the feeding of FHM outweighed the slower rate of growth observed, suggesting that the feeding of FHM should be promoted actively in premature infants.

Early feeding, feeding tolerance, and lactase activity in preterm infants

OBJECTIVE

We sought to ascertain whether the timing of feeding initiation affected the development of intestinal lactase activity and whether there are clinical ramifications of lower lactase activity.

STUDY DESIGN

Preterm infants (26 to 30 weeks' gestation; n = 135) were randomly assigned to begin enteral feedings at either 4 (early group) or 15 days of age (standard group). At 10, 28, and 50 days of age lactase activity was determined by measuring the urinary ratio of lactulose/lactose after the 2 sugars were administered.

RESULTS

Lactase activity increased significantly over time. Infants in the early group had greater lactase activity at 10 days of age (by 100%) and 28 days of age (by 60%) than the standard group. At 10 days of age lactase activity was greater in milk- versus formula-fed infants. The time required to achieve full enteral feedings, the number of abnormal abdominal x-ray examinations, and the total number of abdominal x-ray examinations were inversely related to lactase activity.

CONCLUSIONS

Early feeding increases intestinal lactase activity in preterm infants. Lactase activity is a marker of intestinal maturity and may influence clinical outcomes. Whether the effects of milk on lactase activity were due to the greater concentration of lactose in human milk compared with that in formula must be determined.