Two-hourly versus 3-hourly feeding for very low birthweight infants: a randomised controlled trial

Dilemmas in initiation of very preterm infant enteral feeds-when, what, how?

With limited clinical evidence available to guide common nutritional decisions, significant variation exists in approaches to enteral feeding for very preterm infants, specifically when feedings are initiated, what is fed, and the method used for feedings. Preclinical studies have highlighted the benefits associated with avoiding nil per os and providing early-stage mother's own milk or colostrum. However, these recommended approaches are often mutually exclusive due to the delays in lactation associated with very preterm delivery, resulting in uncertainty regarding which approach should be prioritized. Few studies have evaluated feeding frequency in preterm infants, with limited generalizability to extremely preterm infants. Therefore, even evidence-based approaches to very preterm infant feed initiation can differ. Future research is needed to identify optimal strategies for enteral nutrition in very preterm infants, but, until then, evidence-informed approaches may vary depending on each neonatal intensive care unit's assessment of risk and benefit.

Quality improvement in Kangaroo Mother Care: learning from a teaching hospital

BACKGROUND

Kangaroo Mother Care (KMC) is a low-resource, evidence-based, high-impact intervention for low-birth weight (LBW) care. Quality improvement in KMC requires meso-level, macro-level and micro-level interventions. Our institution, a public teaching hospital, hosts a level-II/III neonatal intensive care unit (NICU). The average demand for beds typically exceeds available capacity, with 60% occupancy attributed to LBW patients. There was low uptake of KMC practice at our unit.

AIM STATEMENT

In the initial phase, we aimed to improve the coverage of KMC in admitted eligible neonates from a baseline of 20%-80% within 15 days. After a period of complacency, we revised the aim statement with a target of improving the percentage of babies receiving 6-hour KMC from 30% to 80% in 12 weeks.

METHODS

We report this quasi-experimental time-series study. With the Point of Care Quality Improvement methodology, we performed Plan-Do-Study-Act (PDSA) cycles to improve KMC practice. We involved all the healthcare workers, mothers and caregivers to customise various KMC tools (KMC book format, KMC bag, mother's gown) and minimise interruptions. Feedback from all levels guided our PDSA cycles.

RESULTS

The percentage of babies receiving at least 1-hour KMC increased from 20% to 100% within 15 days of August 2017. In the improvement phase, baseline 6-hour KMC coverage of 30% increased to 80% within 12 weeks (October-December 2017). It sustained for more than 2 years (January 2018 till February-2020) at 76.5%±2.49%.

CONCLUSIONS

Quality improvement methods helped increase the coverage and percentage of babies receiving 6-hour KMC per day in our NICU. The duration specified KMC coverage should be adopted as the quality indicator of KMC. The training of healthcare workers and KMC provider should include hands-on sessions involving the mother and the baby. Maintaining data and providing suitable KMC tools are necessary elements for improving KMC. Minimising interruption is possible with family support and appropriate scheduling of activities. Having a designated KMC block helps in peer motivation.

Three-hourly versus two-hourly feeding interval in stable preterm infants: an updated systematic review and meta-analysis of randomized controlled trials

Evidence from randomized controlled trials (RCTs) suggests that three-hourly feeding is safe and might help achieve full feeds earlier in preterm infants. We systematically compared the benefits and harms of three-hourly and two-hourly feeding schedules in preterm infants. We searched electronic databases (MEDLINE, CINAHL, Embase, Web of Science, and Scopus) and trial registries until November 16, 2021, for RCTs comparing the two feeding schedules. We did a random-effects meta-analysis using RevMan 5.4 software. The primary outcome was the incidence of stage II or III necrotizing enterocolitis (NEC). Other outcomes were the incidence of any stage NEC, mortality, time to full enteral feeds, and hospital stay. Six trials (872 participants) are included. There was no significant difference in the incidence of stage II/III NEC (3 trials; 530 participants; RR 1.39; 95% CI: 0.53, 3.65; I² - 0%, low certainty), and any stage NEC (5 studies; 767 participants; RR 0.98; 95% CI: 0.53, 1.82; I² -0%, very low certainty) between three and two-hourly feeding groups. There was no difference in achieving full feeds (5 trials; 755 participants; MD: - 0.0 days; 95% CI: - 0.32, 0.31, low certainty) or other outcomes. On subgroup analysis, neonates with birthweight < 1000 g and in the three-hourly feeding regime achieved full enteral feeds slower than those in the two-hourly feeding group (1 trial; 84 participants; MD: 2.9 days, 95% CI: 1.16, 4.64, low certainty).

CONCLUSION

In stable preterm infants (1000-1500 g), three-hourly feeding can be followed safely. In infants < 1000 g, there is insufficient evidence to advise on an optimal feeding interval, although a 2-h interval might be preferable.Prospero Registration Number: CRD42021246568.

WHAT IS KNOWN

• Most of the units follow two-hourly feeding schedules without any evidence. • Recent trials suggest that the three hourly feeding schedules can be safely followed in stable preterm infants.

WHAT IS NEW

• Low certainty evidence suggests that three-hourly feeding is safe in stable preterm infants (1000-1500 grams). • In infants with birthweight <1000 grams, two-hourly feeding may be considered as it was associated with a shorter time to full feeds in subgroup analysis.

A systematic review of the definitions and prevalence of feeding intolerance in preterm infants

BACKGROUND & AIMS

Feeding intolerance (FI) is a common phenomenon experienced in preterm infants in neonatal intensive care units, as well as being a focus of many research studies into feeding methods, particularly in relation to comorbidities. There is no widely accepted definition of FI. This systematic review aimed to explore the range of definitions used for FI and provide an estimate of the prevalence amongst preterm infants.

METHODS

Searches were completed on MEDLINE (includes the Cochrane library), Embase, PsycInfo, CINAHL, NHS Evidence and Web of Science. Inclusion criteria; preterm infants in neonatal units, a clear definition of FI, >10 patients and be available in English language. Case reports were excluded.

RESULTS

One hundred studies were included. Definitions of FI were inconsistent. Studies were grouped according to definition used into: Group A - measuring gastric residual volume (GRV) only; group B - GRV and abdominal distension (AD); group C - GRV, AD and gastrointestinal symptoms (GI) which included any of vomiting, bilious vomiting and blood in stool; group D- GRV and GI; group E - AD and GI; group F - GI only and group G - any other elements used. Meta-analysis demonstrated that prevalence of FI between groups varied from 15 to 30% with an overall prevalence of 27% (95% confidence interval 23-31%). Group A had the highest prevalence. Review of time to full enteral feed was performed (37 studies) which demonstrated a range of 11.3-18.3 days depending on which FI definition used.

DISCUSSION

Definitions of FI in research are inconsistent, a similar finding to that seen in studies in both paediatric and adult critical care populations. The difficulty of defining FI in the preterm population is the concern regarding necrotising enterocolitis, with some studies using an overlap in their definitions, despite differing pathophysiology and management. Due to the heterogeneity of data obtained in this review regarding definitions used, further robust research is required in order to conclude which elements which should be used to define FI in this population.

PROSPERO NUMBER

CRD42019155596. Registered November 2019.

Slow advancement of enteral feed volumes to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

Early enteral feeding practices are potentially modifiable risk factors for necrotising enterocolitis (NEC) in very preterm or very low birth weight (VLBW) infants. Observational studies suggest that conservative feeding regimens, including slowly advancing enteral feed volumes, reduce the risk of NEC. However, it is unclear whether slow feed advancement may delay establishment of full enteral feeding, and if it could be associated with infectious morbidities secondary to prolonged exposure to parenteral nutrition.

OBJECTIVES

To determine the effects of slow rates of enteral feed advancement on the risk of NEC, mortality, and other morbidities in very preterm or VLBW infants.

SEARCH METHODS

We searched CENTRAL (2020, Issue 10), Ovid MEDLINE (1946 to October 2020), Embase via Ovid (1974 to October 2020), Maternity and Infant Care database (MIDIRS) (1971 to October 2020), CINAHL (1982 to October 2020), and clinical trials databases and reference lists of retrieved articles for eligible trials.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials that assessed effects of slow (up to 24 mL/kg/d) versus faster rates of advancement of enteral feed volumes on the risk of NEC in very preterm or VLBW infants.

DATA COLLECTION AND ANALYSIS

Two review authors separately evaluated trial risk of bias, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference. We used the GRADE approach to assess the certainty of evidence. Outcomes of interest were NEC, all-cause mortality, feed intolerance, and invasive infection.

MAIN RESULTS

We included 14 trials involving a total of 4033 infants (2804 infants participated in one large trial). None of the trials masked parents, caregivers, or investigators. Risk of bias was otherwise low. Most infants were stable very preterm or VLBW infants of birth weight appropriate for gestation. About one-third of all infants were extremely preterm or extremely low birth weight (ELBW), and about one-fifth were small for gestational age, growth-restricted, or compromised as indicated by absent or reversed end-diastolic flow velocity in the foetal umbilical artery. Trials typically defined slow advancement as daily increments of 15 to 24 mL/kg, and faster advancement as daily increments of 30 to 40 mL/kg. Meta-analyses showed that slow advancement of enteral feed volumes probably has little or no effect on the risk of NEC (RR 1.06, 95% confidence interval (CI) 0.83 to 1.37; RD 0.00, 95% CI -0.01 to 0.02; 14 trials, 4026 infants; moderate-certainty evidence) or all-cause mortality prior to hospital discharge (RR 1.13, 95% CI 0.91 to 1.39; RD 0.01, 95% CI -0.01 to 0.02; 13 trials, 3860 infants; moderate-certainty evidence). Meta-analyses suggested that slow advancement may slightly increase feed intolerance (RR 1.18, 95% CI 0.95 to 1.46; RD 0.05, 95% CI -0.02 to 0.12; 9 trials, 719 infants; low-certainty evidence) and may slightly increase the risk of invasive infection (RR 1.14, 95% CI 0.99 to 1.31; RD 0.02, 95% CI -0.00 to 0.05; 11 trials, 3583 infants; low-certainty evidence).

AUTHORS' CONCLUSIONS

The available trial data indicate that advancing enteral feed volumes slowly (daily increments up to 24 mL/kg) compared with faster rates probably does not reduce the risk of NEC, death, or feed intolerance in very preterm or VLBW infants. Advancing the volume of enteral feeds at a slow rate may slightly increase the risk of invasive infection.

Short versus long feeding interval for bolus feedings in very preterm infants

BACKGROUND

There is presently no certainty about the ideal feeding intervals for preterm infants. Shorter feeding intervals of, for example, two hours, have the theoretical advantage of allowing smaller volumes of milk. This may have the potential to reduce the incidence and severity of gastro-oesophageal reflux. Longer feeding intervals have the theoretical advantage of allowing more gastric emptying between two feeds. This potentially provides periods of rest (and thus less hyperaemia) for an immature digestive tract.

OBJECTIVES

To determine the safety of shorter feeding intervals (two hours or shorter) versus longer feeding intervals (three hours or more) and to compare the effects in terms of days taken to regain birth weight and to achieve full feeding.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to run comprehensive searches in CENTRAL (2020, Issue 6) and Ovid MEDLINE and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions, and CINAHL on 25 June 2020. We searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs and quasi-RCTs comparing short (e.g. one or two hours) versus long (e.g. three or four hours) feeding intervals in preterm infants of any birth weight, all or most of whom were less than 32 weeks' gestation. Infants could be of any postnatal age at trial entry, but eligible infants should not have received feeds before study entry, with the exception of minimal enteral feeding. We included studies of nasogastric or orogastric bolus feeding, breast milk or formula, in which the feeding interval is the intervention.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used the GRADE approach to assess the certainty of evidence. Our primary outcomes were days taken to achieve full enteral feeding and days to regain birth weight. Our other outcomes were duration of hospital stay, episodes of necrotising enterocolitis (NEC) and growth during hospital stay (weight, length and head circumference).

MAIN RESULTS

We included four RCTs, involving 417 infants in the review. One study involving 350 infants is awaiting classification. All studies compared two-hourly versus three-hourly feeding interval. The risk of bias of the included studies was generally low, but all studies had high risk of performance bias due to lack of blinding of the intervention. Three studies were included in meta-analysis for the number of days taken to achieve full enteral feeding (351 participants). The mean days to achieve full feeds was between eight and 11 days. There was little or no difference in days taken to achieve full enteral feeding between two-hourly and three-hourly feeding, but this finding was of low certainty (mean difference (MD) ‒0.62, 95% confidence interval (CI) ‒1.60 to 0.36). There was low-certainty evidence that the days taken to regain birth weight may be slightly longer in infants receiving two-hourly feeding than in those receiving three-hourly feeding (MD 1.15, 95% CI 0.11 to 2.20; 3 studies, 350 participants). We are uncertain whether shorter feeding intervals have any effect on any of our secondary outcomes including the duration of hospital stay (MD ‒3.36, 95% CI ‒9.18 to 2.46; 2 studies, 207 participants; very low-certainty evidence) and the risk of NEC (typical risk ratio 1.07, 95% CI 0.54 to 2.11; 4 studies, 417 participants; low-certainty evidence). No study reported growth during hospital stay.

AUTHORS' CONCLUSIONS

The low-certainty evidence we found in this review suggests that there may be no clinically important differences between two- and three-hourly feeding intervals. There is insufficient information about potential feeding complications and in particular NEC. No studies have looked at the effect of other feeding intervals and there is no long-term data on neurodevelopment or growth.

Continuous versus bolus intermittent intragastric tube feeding for preterm and low birth weight infants with gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease is a particularly common condition among preterm and low birth weight infants. These infants are more likely to have excessive regurgitation, as they do not have a fully developed antireflux mechanism. Preterm and low birth weight infants who are unable to suck oral feeds are required to be fed via an intragastric tube for varying lengths of time. Intragastric tube feeding can be delivered by the intermittent bolus method or by the continuous feeding method. Use of continuous or intermittent bolus intragastric feeding may have a positive or negative effect on the incidence or severity of gastro-oesophageal reflux disease.

OBJECTIVES

• To determine whether continuous or intermittent bolus intragastric tube feeding reduces the number of episodes and the duration of gastro-oesophageal reflux disease (GORD) in preterm and low birth weight infants • To perform subgroup analyses for gestational age; birth weight; age in days from birth at full enteral feeding via intragastric tube (breast versus bottle); frequency of intermittent bolus feed; and type of medication for treatment of GORD (only if medication was prescribed and was given similarly to both intervention groups) SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 7), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), on 8 July 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

Published and unpublished RCTs and quasi-RCTs were eligible for inclusion in this review, as were cluster-randomised and cross-over randomised trials that compared the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and quality. We planned to use the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We found no trials that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We did not identify any randomised trials that evaluated the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants. Well-designed and adequately powered trials are needed.

Implementing a three-hourly feeding schedule in stable preterm infants to decrease maternal fatigue

BACKGROUND

A three-hourly feeding schedule has been shown to be as safe as a two-hourly schedule in preterm neonates. It saves nursing time and may be less tiring for the mothers. However, tradition and apprehensions have prevented its wider acceptance. We used a quality improvement approach to implement a three-hourly feeding schedule in stable preterm infants >32 weeks postmenstrual age (PMA) in our unit through a series of plan-do-study-act (PDSA) cycles.

METHODS

All preterm neonates >32 weeks PMA, who were on full enteral feeds and without any respiratory support were eligible. The key quantitative outcome was maternal fatigue score. Safety was assessed in terms of episodes of hypoglycaemia and feed intolerance. Qualitative experiences from nursing staff were captured. The volume of expressed breastmilk and requirement of formula feeds were also recorded. After recording baseline data on a two-hourly feeding schedule, four PDSA cycles were sequentially completed over 21 weeks. The results of each PDSA cycle informed the change strategy for the next cycle.

RESULTS

In the baseline phase, five neonates on a two-hourly schedule were studied. In PDSA cycles I, II, III and IV, a cumulative of 122 neonates were studied on a three-hourly schedule. There was a significant decrease in median maternal fatigue score (13 (IQR 8-23) to 3 (IQR 1-6); p=0.01)). Only one neonate had feed intolerance, while two had mild asymptomatic transient hypoglycaemia. Six (5%) neonates were shifted to two-hourly feeds temporarily due to transient reasons. Nursing staff felt mothers could devote more time to Kangaroo mother care. The volume of expressed breastmilk and requirement of formula feeds were not different from the three-hourly schedule.

CONCLUSIONS

It was possible to change the traditional two-hourly feeding schedule to three-hourly in stable preterm infants using a quality improvement approach, while objectively documenting its safety and benefits.

Feeding interval and use of donor breast milk for very low birthweight infants: A nationwide survey in Japan

BACKGROUND

Enteral feeding is critical for postnatal growth of very low birthweight infants (VLBWI); however, a standard feeding strategy has not been established in Japan. A 2- or 3-h feeding interval is generally used, but no clear evidence supports either approach. Additionally, there is no nationwide breast milk bank in Japan and no consensus exists on the use of donor breast milk (DBM). To clarify the current feeding strategies for VLBWI in Japan, we undertook a nationwide survey.

METHODS

We sent a questionnaire to the 382 NICUs included in the Neonatal Research Network in Japan. We sought information on NICU size, number of admissions, necrotizing enterocolitis (NEC) incidence, feeding interval, and use of DBM.

RESULTS

We received responses from 217 NICUs (56.8%), including 76 tertiary centers and 140 regional centers. We only analyzed data obtained from tertiary perinatal centers with a high response rate (77.6%) owing to the insufficient response rate of lower-level facilities (<50%). Most NICUs (71.1%) used a 3-h feeding interval. Only 9.2% used a 2-h interval for all VLBWI. Most NICUs (64.5%) never used DBM, which is not routinely pasteurized. DBM was used in 27 NICUs (35.5%), with and without limitations. Data from 14,233 VLBWI were analyzed; 258 infants (1.8%) were diagnosed with NEC from 2011 to 2015. The incidence of NEC was higher in NICUs that used a 2-h interval (2.7%) than in others. No association was found between NEC and the use of DBM. The NEC incidence did not differ between centers using the most common strategy of a 3-h interval without DBM and those using other strategies.

CONCLUSION

Most NICUs in Japan use a 3-h feeding interval and do not use DBM for VLBWI. Further prospective studies including multiple confounders are required to clarify the relationship between feeding strategy and the incidence of NEC.

Effect of Gastric Residual Evaluation on Enteral Intake in Extremely Preterm Infants: A Randomized Clinical Trial

IMPORTANCE

Evaluating prefeed gastric residuals is considered routine care but has little supporting evidence.

OBJECTIVE

To determine the effect of omitting prefeed gastric residual evaluation on nutritional outcomes in extremely preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

This single-center randomized clinical trial compared the omission of gastric residual evaluation with prefeed gastric residual evaluation. Infants were recruited from a level 4 neonatal intensive care unit and were enrolled from October 17, 2013, to October 8, 2016, and then followed up for 6 weeks after birth. Eligible participants were infants born at 32 or fewer weeks' gestation with a birth weight of 1250 g or less; they were enrolled within 72 hours after birth and within 24 hours after feeding initiation. All participants (N = 143) were included in the modified intent-to-treat analysis, which was conducted from March to July 2018.

INTERVENTIONS

The residual group underwent prefeed gastric residual evaluation; the no residual group did not. Feeding decisions were made according to nutritional guidelines, and infants received only human milk.

MAIN OUTCOMES AND MEASURES

The primary outcome was weekly enteral nutrition intake in mL/kg for 6 weeks after birth.

RESULTS

Of 143 infants, 74 (51.7%) were randomized to undergo gastric residual evaluation (residual group) and 69 (48.3%) to omitted gastric residual evaluation (no residual group). The residual group comprised an even number of male and female infants (37 [50.0%]) with a mean (SD) gestational age of 27.1 (2.4) weeks and a mean (SD) birth weight of 888.8 (206.6) grams, whereas the no residual group had more male infants (36 [52.17%]), a mean (SD) gestational age of 27 (1.2) weeks, and a mean (SD) birth weight of 915.2 (180) grams. The no residual group had feedings that advanced more quickly compared with the residual group (mean weekly increase, 20.7 mL/kg/d vs 17.9 mL/kg/d; P = .02) and consumed more feedings at weeks 5 (137.2 [95% CI, 128.6-145.8]; P = .03) and 6 (141.6 [95% CI, 133.2-150.0]; P = .03). Among the secondary outcomes, the no residual group had higher mean estimated log weights (7.01 [95% CI, 6.99-7.02] vs 6.98 [95% CI, 6.97-7.00]; P = .03), had fewer episodes of abdominal distention (0.59 [95% CI, 0.34-1.01] vs 1.79 [95% CI, 1.27-2.53]; P = .001), and were discharged 8 days earlier (4.21 [95% CI, 4.14-4.28] vs 4.28 [95% CI, 4.19-4.36]; P = .01). Odds for necrotizing enterocolitis (0.058 [95% CI, 0.018-0.190] vs 0.026 [95% CI, 0.006-0.109]), death (0.004 [95% CI, 0.0003-0.046] vs 0.012 [95% CI, 0.001-0.131]), late-onset sepsis (0.970 [95% CI, 0.67-1.40] vs 1.38 [95% CI, 0.97-1.94]), and ventilator-associated pneumonia (0.084 [95% CI, 0.033-0.214] vs 0.056 [95% CI, 0.019-0.168]) were similar between groups.

CONCLUSIONS AND RELEVANCE

Among extremely preterm infants, the omission of gastric residual evaluation increased the delivery of enteral nutrition as well as improved weight gain and led to earlier hospital discharge; these results may translate into evidence-based practice.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01863043.

Three-hourly feeding intervals are associated with faster advancement in very preterm infants

OBJECTIVE

To compare the effect of two-hourly (Q2H) vs. three-hourly (Q3H) feeding on time to achieve full enteral feeding, growth metrics and respiratory tolerance in very preterm infants with birth weight ≤ 1250 g.

STUDY DESIGN

Retrospective study review of 18 months before and after a change in our feeding guideline from Q3H to Q2H feedings.

RESULTS

113 infants were included, 59 in Q3H and 54 in Q2H groups. Q2H infants required 10% more days to achieve full enteral feeding, however it was not statistically significant (P = 0.054). Q2H feeding was associated with 16% more central catheter days (P = 0.02) and 17% more parenteral nutrition days (P = 0.019). There were no differences in respiratory outcomes or growth metrics between the groups.

CONCLUSION

Very preterm infants fed Q3H had less central catheter and parenteral nutrition days when compared to those fed Q2H, without significant differences in growth or respiratory outcomes.

Slow advancement of enteral feed volumes to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

Early enteral feeding practices are potentially modifiable risk factors for necrotising enterocolitis (NEC) in very preterm or very low birth weight (VLBW) infants. Observational studies suggest that conservative feeding regimens, including slowly advancing enteral feed volumes, reduce the risk of NEC. However, slow feed advancement may delay establishment of full enteral feeding and may be associated with metabolic and infectious morbidities secondary to prolonged exposure to parenteral nutrition.

OBJECTIVES

To determine effects of slow rates of enteral feed advancement on the incidence of NEC, mortality, and other morbidities in very preterm or VLBW infants.

SEARCH METHODS

We used the standard Cochrane Neonatal search strategy to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 5), MEDLINE via PubMed (1966 to June 2017), Embase (1980 to June 2017), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to June 2017). We searched clinical trials databases, conference proceedings, previous reviews, and reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that assessed effects of slow (up to 24 mL/kg/d) versus faster rates of advancement of enteral feed volumes upon the incidence of NEC in very preterm or VLBW infants.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial eligibility and risk of bias and independently extracted data. We analysed treatment effects in individual trials and reported risk ratio (RR) and risk difference (RD) for dichotomous data, and mean difference (MD) for continuous data, with respective 95% confidence intervals (CIs). We used a fixed-effect model for meta-analyses and explored potential causes of heterogeneity via sensitivity analyses. We assessed the quality of evidence at the outcome level using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We identified 10 RCTs in which a total of 3753 infants participated (2804 infants participated in one large trial). Most participants were stable very preterm infants of birth weight appropriate for gestation. About one-third of all participants were extremely preterm or extremely low birth weight (ELBW), and about one-fifth were small for gestational age (SGA), growth-restricted, or compromised in utero, as indicated by absent or reversed end-diastolic flow velocity (AREDFV) in the fetal umbilical artery. Trials typically defined slow advancement as daily increments of 15 to 20 mL/kg, and faster advancement as daily increments of 30 to 40 mL/kg. Trials generally were of good methodological quality, although none was blinded.Meta-analyses did not show effects on risk of NEC (typical RR 1.07, 95% CI 0.83 to 1.39; RD 0.0, 95% CI -0.01 to 0.02) or all-cause mortality (typical RR 1.15, 95% CI 0.93 to 1.42; typical RD 0.01, 95% CI -0.01 to 0.03). Subgroup analyses of extremely preterm or ELBW infants, or of SGA or growth-restricted or growth-compromised infants, showed no evidence of an effect on risk of NEC or death. Slow feed advancement delayed establishment of full enteral nutrition by between about one and five days. Meta-analysis showed borderline increased risk of invasive infection (typical RR 1.15, 95% CI 1.00 to 1.32; typical RD 0.03, 95% CI 0.00 to 0.05). The GRADE quality of evidence for primary outcomes was "moderate", downgraded from "high" because of lack of blinding in the included trials.

AUTHORS' CONCLUSIONS

Available trial data do not provide evidence that advancing enteral feed volumes at daily increments of 15 to 20 mL/kg (compared with 30 to 40 mL/kg) reduces the risk of NEC or death in very preterm or VLBW infants, extremely preterm or ELBW infants, SGA or growth-restricted infants, or infants with antenatal AREDFV. Advancing the volume of enteral feeds at a slow rate results in several days of delay in establishing full enteral feeds and may increase the risk of invasive infection.