Early full enteral feeding for preterm or low birth weight infants.

Background: The introduction and advancement of enteral feeds for preterm or low birth weight infants is often delayed because of concerns that early full enteral feeding will not be well tolerated or may increase the risk of necrotising enterocolitis. Early full enteral feeding, however, might increase nutrient intake and growth rates; accelerate intestinal physiological, metabolic, and microbiomic postnatal transition; and reduce the risk of complications associated with intravascular devices for fluid administration.  OBJECTIVES: To determine how early full enteral feeding, compared with delayed or progressive introduction of enteral feeds, affects growth and adverse events such as necrotising enterocolitis, in preterm or low birth weight infants.

Search methods: We used the standard search strategy of Cochrane Neonatal to search Cochrane Central Register of Controlled Trials; MEDLINE Ovid, Embase Ovid, Maternity & Infant Care Database Ovid, the Cumulative Index to Nursing and Allied Health Literature, and clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials to October 2020.

Selection criteria: Randomised controlled trials that compared early full enteral feeding with delayed or progressive introduction of enteral feeds in preterm or low birth weight infants.

Data collection and analysis: We used the standard methods of Cochrane Neonatal. Two review authors separately assessed trial eligibility, evaluated trial quality, extracted data, and synthesised effect estimates using risk ratios (RR), risk differences, and mean differences (MD) with 95% confidence intervals (CI). We used the GRADE approach to assess the certainty of evidence.

Main results: We included six trials. All were undertaken in the 2010s in neonatal care facilities in India. In total, 526 infants participated. Most were very preterm infants of birth weight between 1000 g and 1500 g. Trials were of good methodological quality, but a potential source of bias was that parents, clinicians, and investigators were not masked. The trials compared early full feeding (60 mL/kg to 80 mL/kg on day one after birth) with minimal enteral feeding (typically 20 mL/kg on day one) supplemented with intravenous fluids. Feed volumes were advanced daily as tolerated by 20 mL/kg to 30 mL/kg body weight to a target steady-state volume of 150 mL/kg to 180 mL/kg/day. All participating infants were fed preferentially with maternal expressed breast milk, with two trials supplementing insufficient volumes with donor breast milk and four supplementing with preterm formula.  Few data were available to assess growth parameters. One trial (64 participants) reported a slower rate of weight gain (median difference -3.0 g/kg/day), and another (180 participants) reported a faster rate of weight gain in the early full enteral feeding group (MD 1.2 g/kg/day). We did not meta-analyse these data (very low-certainty evidence). None of the trials reported rate of head circumference growth. One trial reported that the mean z-score for weight at hospital discharge was higher in the early full enteral feeding group (MD 0.24, 95% CI 0.06 to 0.42; low-certainty evidence). Meta-analyses showed no evidence of an effect on necrotising enterocolitis (RR 0.98, 95% CI 0.38 to 2.54; 6 trials, 522 participants; I² = 51%; very low-certainty evidence).

Authors' conclusions: Trials provided insufficient data to determine with any certainty how early full enteral feeding, compared with delayed or progressive introduction of enteral feeds, affects growth in preterm or low birth weight infants. We are uncertain whether early full enteral feeding affects the risk of necrotising enterocolitis because of the risk of bias in the trials (due to lack of masking), inconsistency, and imprecision.