Breast-feeding is associated with fewer comorbidities in very-low-birth-weight (VLBW) preterm infants. Bronchopulmonary dysplasia (BPD) of VLBW infants is a multifactorial pathology in which nutritional aspects may be of special importance. The aim of this study is to determine, in a cohort of VLBW infants, whether breast milk nutrition is associated with a reduced prevalence and severity of BPD. A retrospective study was conducted to record the intake of mother’s own milk (MOM), pasteurised donor human milk or preterm formula milk in the first 2 weeks of postnatal life of 566 VLBW newborns at our hospital during the period January 2008–December 2021. After applying the relevant exclusion criteria, data for 489 VLBW infants were analysed; 195 developed some degree of BPD. Moderate or severe BPD is associated with less weight gain. Moreover, the preferential ingestion of breast milk in the first and second postnatal weeks had effects associated with lower OR for BPD, which were statistically demonstrable for mild (OR 0·16; 95 % CI 0·03, 0·71) and severe (OR 0·08; 95 % CI 0·009, 0·91) BPD. Breast-feeding during the first weeks of postnatal life is associated with a reduced prevalence of BPD, which is frequently associated with less weight gain as a result of greater respiratory effort with greater energy expenditure.

Small for gestational age (SGA) is typically defined as birth weight < 10th percentile for age. Limited data are available regarding the growth of SGA preterm infants in relation to feeding type. We aimed to study SGA preterm infants fed fortified mother’s own milk (MOM) or preterm formula (PF) on growth patterns and catch-up growth at discharge and 2-year corrected age (CA). Our retrospective cohort study included data from medical records and follow-up questionnaires about SGA preterm infants born at < 37 weeks fed on MOM (n 40) and PF (n 40). Weight, length/height and head circumference (HC) were collected at birth, discharge and at 2-year CA, and Δ z-scores were calculated. The MOM group had significantly larger negative change in weight and length z-scores between birth and discharge, and smaller positive change in HC z-score (–0·47 (sd 0·41) v. −0·25 (sd 0·36), P = 0·01; −0·63 (sd 0·75) v. −0·27 (sd 0·75), P = 0·03; 0·13 (sd 0·67) v. 0·41 (sd 0·55), P = 0·04, respectively). Almost half of the MOM-fed infants experienced poor length growth by discharge compared with 22 % of PF-fed infants (P = 0·03). By 2-year CA, both groups had similar positive change in weight and HC z-scores, but MOM-fed infants had a slower increase in height z-score (0·64 (sd 1·30) v. 1·33 (sd 1·33), P = 0·02), and only 40 % had achieved catch-up height compared with 68 % of the PF group (P = 0·02). Our study indicates that fortified MOM-fed SGA preterm infants may need extra nutritional support in the first 2 years of life to achieve height growth potential.

Better understanding of the variation in macronutrient content of human donor milk (HDM) potentiates targeted nutrition for preterm babies. The present study describes the relationship of maternal age, parity, monthly lactation stage estimate (LSEm), daily volume of milk expressed (Vd), sex, gestation and birth weight z scores with macronutrient content of HDM. Multilevel mother–infant pair ID random intercept models were performed using the predictor variables above on the outcome HDM macronutrient content determined using mid-IR spectroscopy. Mean macronutrient content was also compared by gestational age and small for gestational age (SGA) (z score < –1·28) or appropriate for gestational age (AGA) (z score ≥ –1·28) categories. A total of 2966 samples of donations from 1175 mother–infant pairs to the UK Northwest Human Milk Bank between 2011 and 2017 were analysed. Mean protein, fat, carbohydrate and calculated energy were 0·89 (SD 0·24) g/dl, 2·99 (SD 0·96) g/dl, 7·09 (SD 0·44) g/dl, and 60·37 (SD 8·41) kcal/dl (252·59 (SD 35·19) kJ/dl), respectively. Preterm SGA HDM was significantly higher in protein, fat and energy content than term AGA HDM and significantly lower in carbohydrate content than term AGA HDM after controlling for LSEm, Vd and between-subject effects. Degree of prematurity did not influence macronutrient content. Between-subject effects accounted for more of the variance in macronutrient content than the fixed effects in the model. Despite this, SGA status, as well as prematurity, may be an important determinant of macronutrient content in human milk. As bioavailability of macronutrients from HDM is uncertain, studies evaluating growth and body composition in preterm and SGA babies fed HDM are warranted.

Preterm infants whose mothers are unable to produce sufficient breast milk are increasingly being supplemented with pasteurised donor human milk (PDHM) instead of commercial preterm infant formula. Concerns have been raised that this practice can result in reduced growth. This retrospective clinical audit collected data from the medical records of a cohort of preterm infants (≤30 weeks gestational age) receiving either ≥28 d of PDHM (n 53) or ≥28 d of their mother’s own milk (MOM, n 43) with standard fortification supplied to both groups during admission. Weight growth velocity was assessed from regained birth weight to 34+1 weeks’ postmenstrual age (PMA); and weight, length and head circumference were compared at discharge and 12 months (corrected age). At 34+1 weeks’ PMA, the weight growth velocity (g/kg per d) was significantly lower in the PDHM group (15·4 g/kg per d, 95 % CI 14·6, 16·1) compared with the MOM group (16·9 g/kg per d, 95 % CI 16·1, 17·7, P=0·007). However, the increase was still within clinically acceptable limits (>15 g/kg per d) and no significant difference was observed in the weight between the two groups. There was no significant difference in weight between the groups at discharge or at the 12-month corrected gestational age review. Although we demonstrated a significant reduction in the weight growth velocity of preterm infants receiving PDHM at 34 weeks’ PMA, this difference is not present at discharge, suggesting that the growth deficit is reduced by supplementation before discharge.