A Systematic Review and Meta-Analysis of Human Milk Feeding and Short-Term Growth in Preterm and Very Low Birth Weight Infants

Growth at 2 years corrected age in preterm infants discharged on two different breast milk enhancements: An observational study

OBJECTIVE

Breast milk (BM) enhancement is often used to meet the nutritional needs of preterm infants after hospital discharge to achieve optimal growth. This study compared growth at 18-28 months corrected age (CA) among very preterm (VP) and very low birth weight (VLBW) infants discharged from the neonatal intensive care units (NICUs) on two BM enhancements.

METHODS

We conducted a retrospective chart review study of infants born between January 1, 2013 and December 31, 2017, with gestational age < 32 weeks or birthweight < 1500 g, discharged from the NICU on BM enhancements; fortification of BM with infant formula additives (BM-F) or unfortified BM supplemented with bottle feeds of infant formula (BM-S). BM enhancements were nonrandomized and determined by the medical team. A linear mixed model regression analysis with propensity score matching was used to estimate the adjusted associations between the nutrition plan at discharge and growth outcomes at 18-28 months CA follow-up.

RESULTS

Two hundred and fifty-one VLBW/VP infants were included. Compared with BM-S, infants discharged on BM-F were more likely to continue receiving BM at 8-12 months CA, and had lower head circumference, weight-for-length z scores, and higher incidence of moderate malnutrition (p ≤ 0.01). After adjusting for confounders, discharge on BM-F was associated with a lower incidence of overweight/obesity at 18-28 months CA (odds interval: 0.45; confidence interval: 0.21-0.96; p = 0.04).

CONCLUSIONS

This retrospective study suggests that VLBW/VP infants discharged on BM-F received BM longer, had lower growth parameter and were less likely to be overweight/obese at 18-28 months CA. Further studies are needed to evaluate the role of postdischarge nutrition on preterm born children's growth, metabolic disease, and neurodevelopmental outcomes.

Breastmilk use in preterm infants <29 weeks' gestational age in Australia, New Zealand and Singapore

AIMS

To describe the prevalence of use of breastmilk and explore demographic characteristics and clinical outcomes associated with breastmilk provision in infants born <29 weeks' gestational age in Australia, New Zealand and Singapore.

METHODS

This is a secondary analysis of data from a randomised controlled trial, which enrolled 1273 infants in 13 neonatal units across Australia, New Zealand and Singapore from 2012 to 2015. Infants were classified as formula-fed, donor milk-fed or mother's milk-fed at their first enteral feed and separately, at hospital discharge.

RESULTS

The percentage of infants receiving mother's own milk differed between centres both at first feed (79% to 100%), and at hospital discharge (47.1% to 71.6%). Aboriginal, Torres Strait Islander and Southeast Asian heritage, drug use and smoking were associated with lower rates of fully breastmilk feeding at hospital discharge. There was no significant difference in growth outcomes, length of stay and feeding tolerance between feeding groups.

CONCLUSIONS

Achieving high breastmilk feeding rates at hospital discharge for all preterm infants born <29 weeks' gestational age at hospital discharge is possible; however, targeted support for mothers who are Indigenous, Southeast Asian and/or using recreational drugs and/or smoking and/or experiencing social disadvantage may be needed. A better understanding and shared knowledge of practice variations within neonatal units with high breastfeeding rates could improve breastmilk access and equity for preterm infants.

AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY

ACTRN12612000503820.

Mother's Own Milk Compared With Formula Milk for Feeding Preterm or Low Birth Weight Infants: Systematic Review and Meta-analysis

OBJECTIVES

We assessed the effect of feeding preterm or low birth weight infants with infant formula compared with mother's own milk on mortality, morbidity, growth, neurodevelopment, and disability.

METHODS

We searched Medline (Ovid), Embase (Ovid), and Cochrane Central Register of Controlled Studies to October 1, 2021.

RESULTS

Forty-two studies enrolling 89 638 infants fulfilled the inclusion criteria. We did not find evidence of an effect on mortality (odds ratio [OR] 1.26, 95% confidence interval [CI] 0.91-1.76), infection (OR 1.52, 95% CI 0.98-2.37), cognitive neurodevelopment (standardized mean difference -1.30, 95% CI -3.53 to 0.93), or on growth parameters. Formula milk feeding increased the risk of necrotizing enterocolitis (OR 2.99, 95% CI 1.75-5.11). The Grading of Recommendations Assessment, Development, and Evaluation certainty of evidence was low for mortality and necrotizing enterocolitis, and very low for neurodevelopment and growth outcomes.

CONCLUSIONS

In preterm and low birth weight infants, low to very low-certainty evidence indicates that feeding with infant formula compared with mother's own milk has little effect on all-cause mortality, infection, growth, or neurodevelopment, and a higher risk of developing necrotizing enterocolitis.

Exclusive Maternal Milk Compared With Exclusive Formula on Growth and Health Outcomes in Very-Low-Birthweight Preterm Infants: Phase II of the Pre-B Project and an Evidence Analysis Center Systematic Review

As part of the Pre-B Project, a systematic review was conducted to evaluate associations between exclusive maternal milk (≥75%) intake and exclusive formula intake and growth and health outcomes in very-low-birthweight (VLBW) preterm infants. The protocols from the Academy of Nutrition and Dietetics' Evidence Analysis Center and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist were followed. Thirteen observational studies were included; 11 studies reported data that could be synthesized in a pooled analysis. The evidence is very uncertain (very low quality) about the effect of exclusive maternal milk on all outcomes due to observational study designs and risk of selection, performance, detection, and reporting bias in most of the included studies. Very-low-quality evidence suggested that providing VLBW preterm infants with exclusive maternal milk was not associated with mortality, risk of necrotizing enterocolitis, sepsis, or developing bronchopulmonary dysplasia, as compared with exclusive preterm formula, but exclusive maternal milk was associated with a lower risk of retinopathy of prematurity (very low certainty). Results may change when additional studies are conducted. There was no difference in weight, length, and head circumference gain between infants fed fortified exclusive maternal milk and infants receiving exclusive preterm formula; however, weight and length gain were lower in infants fed non-fortified exclusive maternal milk. Given the observational nature of human milk research, cause-and-effect evidence was lacking for VLBW preterm infants.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=86829, PROSPERO ID: CRD42018086829.