This meta-analysis assessed short-term outcomes after using human milk-derived fortifiers (HMFs) compared with bovine milk fortifiers (BMFs) in preterm infants fed an exclusive human milk (HM) diet, either mother’s own milk (MOM) or donor human milk (DHM). We searched PubMed, Embase, Google Scholar, CENTRAL and CINHAL between January 2015 and August 2023 for studies reporting outcomes in infants with ≤28 weeks gestation and/or birthweight ≤ 1500 g on an exclusive human milk diet fortified with HMF versus BMF. The primary outcomes were death and NEC (stage ≥ 2). Four studies with a total of 681 infants were included. Mortality was significantly lower in infants fed with an HM-HMFs diet (four studies, 681 infants; RR = 0.50, 95% CI = 0.26–0.94; p = 0.03; I² = 0%), NEC was similar between the two groups (four studies, 681 infants; RR = 0.48, 95% CI = 0.20–1.17; p = 0.11; I²= 39%). BPD was higher in the HM-BMFs group (four studies, 663 infants; RR = 0.83, 95% CI = 0.69–1.000; p = 0.05, I² = 0%), although not statistically significant. No differences were found for sepsis (RR = 0.97, 95% CI = 0.66–1.42; p = 0.96; I² = 26%) or combined ROP (four studies, 671 infants; RR = 0.64, 95% CI = 0.53–1.07; p = 0.28; I² = 69%). An HM-HMFs diet could possibly be associated with decreased mortality with no association with NEC, BPD, sepsis, or ROP. This meta-analysis was limited by the small number of studies included. However, the results should not be refuted for this reason as they provide an impetus for subsequent clinical trials to assess the observed associations.

Chorioamnionitis, a risk factor for bronchopulmonary dysplasia in preterm infants, causes an influx of inflammatory cells into the fetal lung. Using a fetal sheep model, we evaluated the time course of activation, functional maturity, and apoptosis of the leukocytes recruited to the fetal air spaces by lipopolysaccharide (LPS). Time-mated sheep were given intra-amniotic injections with 10 mg of Escherichia coli LPS or saline 2 or 7 days before preterm delivery at 124 days of gestation (term is 150 days). Both neutrophils and monocytes in bronchoalveolar lavage fluid (BALF) had activated NF-κB after 2- and 7-day LPS exposures. These neutrophils and monocytes expressed the activation factor CD11b and the maturation factor PU.1 at 2 days, and increased PU.1 expression was detected in macrophages at 7 days. Leukocyte oxidative burst activity was greatest at 7 days. BALF lipid peroxidation increased fivefold at 2 days, while protein carbonyls increased eightfold at 7 days. Nitrative stress was not detected in the BALF, but leukocytes in the lung expressed nitric oxide synthase (NOS)II (inducible NOS). BALF leukocytes expressed the antioxidant peroxiredoxin V. Lung glutathione peroxidase was also increased with LPS exposure. There was minimal apoptosis of airway and lung leukocytes assessed by caspase-3 activation. Intra-amniotic LPS recruits leukocytes to the fetal air space that have a persistent activation. These results have implications for the pathogenesis of lung inflammatory disorders in the preterm.

Early detection of late-onset sepsis (LOS) in preterm infants is crucial since timely treatment initiation is a key prognostic factor. We hypothesized that fecal volatile organic compounds (VOCs), reflecting microbiota composition and function, could serve as a non-invasive biomarker for preclinical pathogen-specific LOS detection. Fecal samples and clinical data of all preterm infants (≤30 weeks’ gestation) admitted at nine neonatal intensive care units in the Netherlands and Belgium were collected daily. Samples from one to three days before LOS onset were analyzed by gas chromatography—ion mobility spectrometry (GC-IMS), a technique based on pattern recognition, and gas chromatography—time of flight—mass spectrometry (GC-TOF-MS), to identify unique metabolites. Fecal VOC profiles and metabolites from infants with LOS were compared with matched controls. Samples from 121 LOS infants and 121 matched controls were analyzed using GC-IMS, and from 34 LOS infants and 34 matched controls using GC-TOF-MS. Differences in fecal VOCs were most profound one and two days preceding Escherichia coli LOS (Area Under Curve; p-value: 0.73; p = 0.02, 0.83; p < 0.002, respectively) and two and three days before gram-negative LOS (0.81; p < 0.001, 0.85; p < 0.001, respectively). GC-TOF-MS identified pathogen-specific discriminative metabolites for LOS. This study underlines the potential for VOCs as a non-invasive preclinical diagnostic LOS biomarker.

Background and Objective: The effects of neonatal hypoglycemia on the developing brain are well known, resulting in poor neurological outcomes. We aimed to perform an updated meta-analysis on neonatal hypoglycemia, the severity of hypoglycemia, and the associated neurodevelopmental outcomes from infancy to adulthood. Methods: A systematic literature search was conducted from inception until March 2024, using the PubMed, CINAHL, Embase, and the CENTRAL databases. Randomized/quasi-randomized trials and observational studies that evaluated at least one of the pre-specified outcomes were included. A random-effects model meta-analysis was performed to yield the pooled OR and its 95% CI for each outcome due to the expected heterogeneity in the studies. The study findings were reported as per the PRISMA guidelines. Neurodevelopmental impairment (NDI), cognitive impairment, and visual-motor or visual impairment were the primary outcomes. Results: A total of 17 studies (19 publications) were included in the final analysis. NDI, as defined by authors, was significantly higher in early- (OR = 1.16; 95% CI = 1.11–1.43) and mid-childhood (OR = 3.67; 95%CI = 1.07–12.2) in infants with neonatal hypoglycemia. ‘Any cognitive impairment’ was significantly more common in infants with neonatal hypoglycemia (OR = 2.12; 95%CI = 1.79–2.52). Visual-motor impairment (OR = 3.33; 95%CI = 1.14–9.72) and executive dysfunction (OR = 1.99; 95%CI = 1.36–2.91) were also more common in the hypoglycemic group. No difference in the incidence of epilepsy, motor impairment, emotional-behavioral problems, or hearing impairment were noted. Certainty of evidence was adjudged as ‘low’ to ‘very low’ for most outcomes. The severity of hypoglycemia was studied at different intervals, with NDI more common with a blood glucose interval between 20 and 34 mg/dL (1.1–1.9 mmol/L). Conclusions: Low-quality evidence from large observational studies finds a significant association with hypoglycemia in the early neonatal period and long-term neurodevelopmental problems. Additional studies with long enough follow-up are paramount to determine the cut-off concentration and to quantify the impact beyond the infancy period.

Bronchopulmonary dysplasia (BPD) and poor neurodevelopmental outcome after preterm birth are closely associated. However, mechanistic links are uncertain. We are exploring the hypothesis that decreased circulating insulin-like growth factor (IGF)-1 after preterm birth due to the abrupt end of supply by the placenta impairs growth during critical windows of development in most organs, including the lung and brain. Throughout gestation, the fetus uses glycolysis as its main source of energy. Metabolism is mainly stopped at pyruvate, which serves as a “metabolic crossroad”, allowing for the production of amino acids and other “building blocks” for new cells. Metabolic pathways are differentially regulated in the nucleus and the cytoplasm. The ratio between pyruvate dehydrogenase (PDH) and pyruvate dehydrogenase kinase (PDK) determines the biochemical activity which irreversibly metabolizes pyruvate to acetyl-co-A. Metabolites in the nucleus modulate epigenetic remodeling, an essential mechanism of normal growth and maturation during development. IGF-1 has been shown to contribute significantly to the development of virtually all organs, especially related to the regulation of microvascular growth, based on extensive studies of the brain, retina, lung, and intestine. With a preterm birth, the abrupt withdrawal of the placental supply of IGF-1 and its local production directly affects metabolism and microvascular development, which may contribute to a high risk for organ maldevelopment and injury after birth. We speculate that reduced bioavailability of IGF-1 is a possible link between lung and brain development disruption and increases susceptibility for major pulmonary and neurocognitive morbidities in preterm babies. Key Points

Background The addition of budesonide (Bud) 0.25 mg/kg to surfactant decreased the lung and systemic responses to mechanical ventilation in preterm sheep and the rates and severity of bronchopulmonary dysplasia (BPD) in preterm infants. We hypothesized that lower budesonide concentrations in surfactant will decrease injury while decreasing systemic corticosteroid exposure. Methods Preterm lambs received either (1) protective tidal volume (V_T) ventilation with surfactant from birth or (2) injurious V_T ventilation for 15 min and then surfactant treatment. Lambs were further assigned to surfactant mixed with (i) Saline, (ii) Bud 0.25 mg/kg, (iii) Bud 0.1 mg/kg, or (iv) Bud 0.04 mg/kg. All lambs were then ventilated with protective V_T for 6 h. Results Plasma Bud levels were proportional to the dose received and decreased throughout ventilation. In both protective and injurious V_T ventilation, <4% of Bud remained in the lung at 6 h. Some of the improvements in physiology and markers of injury with Bud 0.25 mg/kg were also found with 0.1 mg/kg, whereas 0.04 mg/kg had only minimal effects. Conclusions Lower doses of Bud were less effective at decreasing lung and systemic inflammation from mechanical ventilation. The plasma Bud levels were proportional to dose given and the majority left the lung.