Breastfeeding outcomes in late preterm infants: A multi-centre prospective cohort study

OBJECTIVES: To describe (1) infant feeding practices during initial hospitalisation and up to 6 months corrected age (CA) in infants born late preterm with mothers intending to breastfeed, (2) the impact of early feeding practices on hospital length of stay and (3) maternal and infant factors associated with duration of breastfeeding. METHODS: We conducted a prospective cohort study of infants born at 34⁺⁰ to 36⁺⁶ weeks gestational age during 2018-2020. Families were followed up until the infant reached 6 months of age (corrected for prematurity). Feeding practices during the birth hospitalisation, length of initial hospital stay, and the prevalence of exclusive or any breastfeeding at 6 weeks, 3 months, and 6 months CA were examined. Associations between maternal and infant characteristics and breastfeeding at 6 weeks, 3 months and 6 months CA were assessed using multivariable logistic regression models. RESULTS: 270 infants were enrolled, of these, 30% were multiple births. Overall, 78% of infants received only breastmilk as their first feed, and 83% received formula during the hospitalisation. Seventy-four per cent of infants were exclusively breastfed at discharge, 41% at 6 weeks CA, 35% at 3 months CA, and 29% at 6 months CA. The corresponding combined exclusive and partial breastfeeding rates (any breastfeeding) were 72%, 64%, and 53% of babies at 6 weeks CA, 3 months CA, and 6 months CA, respectively. The mean duration of hospitalisation was 2.9 days longer (95% confidence interval (CI) 0.31, 5.43 days) in infants who received any formula compared with those receiving only breastmilk (adjusted for GA, maternal age, multiple birth, site, and neonatal intensive care unit admission). In multivariable models, receipt of formula as the first milk feed was associated with a reduction in exclusive breastfeeding at 6 weeks CA (odds ratio = 0.22; 95% CI 0.09 to 0.53) and intention to breastfeed >6 months with an increase (odds ratio = 4.98; 95% CI 2.39 to 10.40). Intention to breastfeed >6 months remained an important predictor of exclusive breastfeeding at 3 and 6 months CA. CONCLUSIONS: Our study demonstrates that long-term exclusive breastfeeding rates were low in a cohort of women intending to provide breastmilk to their late preterm infants, with approximately half providing any breastmilk at 6 months CA. Formula as the first milk feed and intention to breastfeed >6 months were significant predictors of breastfeeding duration. Improving breastfeeding outcomes may require strategies to support early lactation and a better understanding of the ongoing support needs of this population.Amy Keir, Alice Rumbold, Carmel T. Collins, Andrew J. McPhee, Jojy Varghese, Scott Morris, Thomas R. Sullivan, Shalem Leemaqz, Philippa Middleton, Maria Makrides, Karen P. Bes

Comparison of different protein concentrations of human milk fortifier for promoting growth and neurological development in preterm infants

BACKGROUND:Human milk alone may provide inadequate amounts of protein to meet the growth requirements of preterm infants because of restrictions in the amount of fluid they can tolerate. It has become common practice to feed preterm infants with breast milk fortified with protein and other nutrients but there is debate about the optimal concentration of protein in commercially available fortifiers. OBJECTIVES:To compare the effects of different protein concentrations in human milk fortifier, fed to preterm infants, on growth and neurodevelopment. SEARCH METHODS:We used the standard search strategy of Cochrane Neonatal to search CENTRAL (2019, Issue 8), Ovid MEDLINE and CINAHL on 15 August 2019. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. SELECTION CRITERIA:We included all published and unpublished randomised, quasi-randomised and cluster-randomised trials comparing two different concentrations of protein in human milk fortifier. We included preterm infants (less than 37 weeks' gestational age). Participants may have been exclusively fed human milk or have been supplemented with formula. The concentration of protein was classified as low (< 1g protein/100 mL expressed breast milk (EBM)), moderate (≥ 1g to < 1.4g protein/100 mL EBM) or high (≥ 1.4g protein/100 mL EBM). We excluded trials that compared two protein concentrations that fell within the same category. DATA COLLECTION AND ANALYSIS:We undertook data collection and analyses using the standard methods of Cochrane Neonatal. Two review authors independently evaluated trials. Primary outcomes included growth, neurodevelopmental outcome and mortality. Data were synthesised 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 the evidence. MAIN RESULTS:We identified nine trials involving 861 infants. There is one trial awaiting classification, and nine ongoing trials. The trials were mostly conducted in infants born < 32 weeks' gestational age or < 1500 g birthweight, or both. All used a fortifier derived from bovine milk. Two trials fed infants exclusively with mother's own milk, three trials gave supplementary feeds with donor human milk and four trials supplemented with preterm infant formula. Overall, trials were small but generally at low or unclear risk of bias. High versus moderate protein concentration of human milk fortifier There was moderate certainty evidence that a high protein concentration likely increased in-hospital weight gain compared to moderate concentration of human milk fortifier (MD 0.66 g/kg/day, 95% CI 0.51 to 0.82; trials = 6, participants = 606). The evidence was very uncertain about the effect of high versus moderate protein concentration on length gain (MD 0.01 cm/week, 95% CI -0.01 to 0.03; trials = 5, participants = 547; very low certainty evidence) and head circumference gain (MD 0.00 cm/week, 95% CI -0.01 to 0.02; trials = 5, participants = 549; very low certainty evidence). Only one trial reported neonatal mortality, with no deaths in either group (participants = 45). Moderate versus low protein concentration of human milk fortifier A moderate versus low protein concentration fortifier may increase weight gain (MD 2.08 g/kg/day, 95% CI 0.38 to 3.77; trials = 2, participants = 176; very low certainty evidence) with little to no effect on head circumference gain (MD 0.13 cm/week, 95% CI 0.00 to 0.26; I² = 85%; trials = 3, participants = 217; very low certainty evidence), but the evidence is very uncertain. There was low certainty evidence that a moderate protein concentration may increase length gain (MD 0.09 cm/week, 95% CI 0.05 to 0.14; trials = 3, participants = 217). Only one trial reported mortality and found no difference between groups (RR 0.48, 95% CI 0.05 to 5.17; participants = 112). No trials reported long term growth or neurodevelopmental outcomes including cerebral palsy and developmental delay. AUTHORS' CONCLUSIONS:Feeding preterm infants with a human milk fortifier containing high amounts of protein (≥ 1.4g/100 mL EBM) compared with a fortifier containing moderate protein concentration (≥ 1 g to < 1.4 g/100 mL EBM) results in small increases in weight gain during the neonatal admission. There may also be small increases in weight and length gain when infants are fed a fortifier containing moderate versus low protein concentration (< 1 g protein/100 mL EBM). The certainty of this evidence is very low to moderate; therefore, results may change when the findings of ongoing studies are available. There is insufficient evidence to assess the impact of protein concentration on adverse effects or long term outcomes such as neurodevelopment. Further trials are needed to determine whether modest increases in weight gain observed with higher protein concentration fortifiers are associated with benefits or harms to long term growth and neurodevelopment.Gao C, Miller J, Collins CT, Rumbold A

Safety and efficacy of human milk-based fortifier in enterally fed preterm and/or low birthweight infants: a systematic review and meta-analysis

OBJECTIVE:To conduct a systematic review and meta-analysis of the efficacy and safety of fortification of human milk with human milk-based fortifier versus cow's milk-based fortifier for use in preterm and/or very low birthweight infants. DESIGN:Randomised or quasi-randomised controlled trials comparing the effect of human milk fortification with human milk-based milk fortifier versus cow's milk-based fortifier in infants born <34 weeks' gestation and/or with birth weight <1500 g were identified by searching databases, clinical trial registries and reference lists until 5 November 2019. Two authors independently extracted data and assessed evidence quality. Meta-analyses were conducted using fixed or random effects models, as appropriate. MAIN OUTCOME MEASURES:Necrotising enterocolitis (Bell's stage II or higher) and late-onset sepsis. RESULTS:Of 863 unique records identified, 16 full-text trials were screened and 2 trials involving 334 infants were included. Primary outcome data were available for 332 infants. Use of human milk-based fortifier compared with cow's milk-based fortifier reduced the risk of necrotising enterocolitis (risk ratio 0.47, 95% CI 0.22 to 0.98). There was no clear evidence of an effect on late-onset sepsis or any other outcomes. The quality of evidence was low to very low due to imprecision and lack of blinding in one study. CONCLUSIONS:Findings suggest that there is a reduction in the incidence of necrotising enterocolitis with human milk-based fortifiers compared with cow's milk-based fortifiers. The overall quality of evidence is low. Further appropriately powered trials are required before this intervention can be routinely recommended for preterm infants.Erin Grace, Cathie Hilditch, Judith Gomersall, Carmel T Collins, Alice Rumbold, Amy K Keir ... et al