Lipid metabolism in pregnancy delivers PUFAs from maternal liver to the developing fetus. The transition at birth to diets less enriched in PUFA is especially challenging for immature, extremely preterm infants who are typically supported by total parenteral nutrition. The aim was to characterize phosphatidylcholine (PC) and choline metabolism in preterm infants and demonstrate the molecular specificity of PC synthesis by the immature preterm liver in vivo. This MS-based lipidomic study quantified the postnatal adaptations to plasma PC molecular composition in 31 preterm infants <28 weeks’ gestational age. Activities of the cytidine diphosphocholine (CDP-choline) and phosphatidylethanolamine-N-methyltransferase (PEMT) pathways for PC synthesis were assessed from incorporations of deuterated methyl-D₉-choline chloride. The concentration of plasma PC in these infants increased postnatally from median values of 481 (IQR: 387–798) µM at enrollment to 1046 (IQR: 616–1220) µM 5 d later (P < 0.001). Direct incorporation of methyl-D₉-choline demonstrated that this transition was driven by an active CDP-choline pathway that synthesized PC enriched in species containing oleic and linoleic acids. A second infusion of methyl-D₉-choline chloride at day 5 clearly indicated continued activity of this pathway. Oxidation of D₉-choline through D₉-betaine resulted in the transfer of 1 deuterated methyl group to S-adenosylmethionine. A very low subsequent transfer of this labeled methyl group to D₃-PC indicated that liver PEMT activity was essentially inactive in these infants. This study demonstrated that the preterm infant liver soon after birth, and by extension the fetal liver, was metabolically active in lipoprotein metabolism. The low PEMT activity, which is the only pathway for endogenous choline synthesis and is responsible for hormonally regulated export of PUFAs from adult liver, strongly supports increased supplementation of preterm parenteral nutrition with both choline and PUFAs.

Although premature infants are increasingly surviving the neonatal period, up to one-third develop bronchopulmonary dysplasia (BPD). Despite evidence that bacterial colonization of the neonatal respiratory tract by certain bacteria may be a risk factor in BPD development, little is known about the role these bacteria play. The aim of this study was to investigate the use of culture-independent molecular profiling methodologies to identify potential etiological agents in neonatal airway secretions. This study used terminal restriction fragment length polymorphism (T-RFLP) and clone sequence analyses to characterize bacterial species in endo-tracheal (ET) aspirates from eight intubated pre-term infants. A wide range of different bacteria was identified in the samples. Forty-seven T-RF band lengths were resolved in the sample set, with a range of 0-15 separate species in each patient. Clone sequence analyses confirmed the identity of individual species detected by T-RFLP. We speculate that the identification of known opportunistic pathogens including S. aureus, Enterobacter sp., Moraxella catarrhalis, Pseudomonas aeruginosa and Streptococcus sp., within the airways of pre-term infants, might be causally related to the subsequent development of BPD. Further, we suggest that culture-independent techniques, such as T-RFLP, hold important potential for the characterization of neonatal conditions, such as BPD.

Multiplex, real-time PCR for the identification of Ureaplasma urealyticum and Ureaplasma parvum was performed on nucleic acids extracted from sequential endotracheal aspirates obtained from preterm neonates born at <29 weeks of gestation and ventilated for more than 48 h admitted to two level 3 neonatal intensive care units. Specimens were obtained shortly after birth and sequentially up until extubation. One hundred fifty-two specimens (93.8%) contained material suitable for analysis. Ureaplasma spp. were identified in 5 of 13 neonates studied. In most cases, the DNA load of the detected Ureaplasma species was low and decreased over time. In addition, changes in detectable Ureaplasma species DNA did not relate to changes in the inflammatory marker C-reactive protein (CRP) or respiratory status. All but two blood samples obtained at times of suspected sepsis were culture positive for other microorganisms; the species cultured were typically coagulase-negative staphylococci and were associated with increased levels of CRP (>10 mg/liter). This study was limited by the small number of patients examined and does not have the power to support or contradict the hypothesis that postnatal lung infection with Ureaplasma parvum is causally related to bronchopulmonary dysplasia (BPD) or adverse respiratory outcomes after preterm birth. However, in this study, increases in CRP levels were not associated with patients in whom Ureaplasma parvum was detected, in contrast to the detection of other bacterial species.

Hypoxic-ischaemic encephalopathy (HIE) in the newborn baby is a major contributor to neonatal mortality and morbidity across the world. Therapeutic hypothermia (TH) is the current standard treatment for moderate to severe HIE, but not all babies benefit. Potential neuroprotective actions of progesterone (PROG) include anti-apoptotic, anti-inflammatory, and anti-oxidative effects and reduction of energy depletion, tissue/cellular oedema, and excitotoxicity. In pre-clinical studies of neonatal HIE, PROG has neuroprotective properties but has not been the subject of systematic review. Here, our objective was to evaluate the evidence base for PROG as a potential therapeutic agent in HIE. The PICO framework was used to define the following inclusion criteria. Population: human neonates with HIE/animal models of HIE; intervention: PROG +/− other agents; comparison: V.S. control; outcome: pathological, neurobehavioural, and mechanistic outcome measures. Medline, EMBASE, and CINHAL were then searched between August to October 2018 using pre-defined medical subject heading and keywords. Study inclusion, data extraction, and risk of bias (ROB) analysis using the SYRCLE ROB tool were carried out by two authors. 14 studies were included in the review. They typically displayed a high ROB. This systematic review suggests that PROG reduced neuropathology and reduced neurobehavioural deficits post-hypoxic-ischaemic (HI) insult in 8 and 3 studies, respectively. However, there was sex dimorphism in the effects of PROG. In addition, there are limitations and biases in these studies, and there remains a need for well-designed large pre-clinical studies with greater methodological quality to further inform the efficacy, safety, dose, timing, and frequency of PROG administration. With such data, large animal studies could be planned combining PROG administration with and without TH.