Objective: To characterize the metabolic variation in neonatal hair samples associated with intrauterine growth discordance in dichorionic-diamniotic (DCDA) twins and to evaluate the effects of specific metabolic alterations on later neurobehavioural outcomes in infancy. Design: Cohort-based case-control study Setting: Peking University Third Hospital Population: DCDA twins with birth weight discordance(DCDA-D) and birthweight concordance (DCDA-C) within a twin cohort recruited between September 2017 and December 2018 in Beijing, China. Methods: A specific hair metabolic profile of 14 pairs of DCDA-D twins was revealed using gas chromatography-mass spectrometry by comparing that of 28 pairs of DCDA-C twins. Pearson’s correlation was used to assess the relationship between the neonatal hair metabolome and neurocognitive outcomes, assessed using the Ages and the Infant’s Stages Questionnaires, third edition (ASQ-3) at 2 or 3 years of age. Main outcome measure: neonatal hair metabolome and long-term neurodevelopment. Results: A total of seventeen hair metabolites were significantly different within DCDA-D twin pairs compared to DCDA-C twins. Particularly, reduced levels of cysteine, threonine, and leucine were identified in both the larger and smaller DCDA-D twins compared with DCDA-C twins. The deregulated metabolic pathways including cysteine, methionine, aminoacyl-tRNA, nicotinate, and nicotinamide metabolism biosynthesis pathways in DCDA-D groups were positively correlated with infant neurocognitive development at 2 or 3 years of age, especially in problem-solving domains. Conclusion: Neonatal hair metabolic variations in utero of growth discordance in DCDA twins may be associated with poor neurocognitive development. Metabolome profiles of hair may be novel predictors of infant neurodevelopment longitudinally.

Plastic bronchitis in a toddler born preterm Jinfang Yuan M.D, Ling Liu M.D, Wei Zhou M.D, Xiaomei Tong M.D, Tongyan Han M.D Department of Pediatric, Peking University Third Hospital, Beijing, China

Plastic bronchitis is identified by the presence of branching mucoid bronchial casts that obstruct airways. It is an uncommon condition, which was more described in lung disease and post-surgery congenital heart disease. We reported a case of a 26-month-old boy born at 29+6 weeks who presented with cough, wheezing and respiratory distress secondary to atelectasis of the left lung. After admission, the patient was treated with intravenous injection of azithromycin and methylprednisolone, inhaled bronchodilators, inhaled budesonide with short-acting beta-agonists and inhaled nebulized N-acetylcysteine. Dramatically, the patient expelled large casts, shaping as the tracheobronchial tree after a severe cough just on the night before the bronchoscopy. In toddlers who were born preterm with recurrent wheezing, the discharge of airway mucus secretion is altered, and the possibility of bronchial plastics needs to be alert.