Gestational Exposure to PM2.5 and Specific Constituents, Meconium Metabolites, and Neonatal Neurobehavioral Development: A Cohort Study.

Exposure to fine particulate matter (PM2.5) during pregnancy has been inversely associated with neonatal neurological development. However, the associations of exposure to specific PM2.5 constituents with neonatal neurological development remain unclear. We investigated these associations and examined the mediating role of meconium metabolites in a Chinese birth cohort consisting of 294 mother-infant pairs. Our results revealed that exposure to PM2.5 and its specific constituents (i.e., organic matter, black carbon, sulfate, nitrate, and ammonium) in the second trimester, but not in the first or third trimester, was inversely associated with the total neonatal behavioral neurological assessment (NBNA) scores. The PM2.5 constituent mixture in the second trimester was also inversely associated with NBNA scores, and sulfate was identified as the largest contributor. Furthermore, meconium metabolome analysis identified four metabolites, namely, threonine, lysine, leucine, and saccharopine, that were associated with both PM2.5 constituents and NBNA scores. Threonine was identified as an important mediator, accounting for a considerable proportion (14.53-15.33%) of the observed inverse associations. Our findings suggest that maternal exposure to PM2.5 and specific constituents may adversely affect neonatal behavioral development, in which meconium metabolites may play a mediating role.

The effects of topical iodine containing antiseptics on thyroidal status and early neurodevelopment of preterm infants.

OBJECTIVES: The goal of this study was to determine the quality of these disinfectants' effects on thyroid function and neurological scores in premature newborns aged 28 to 36 gestational weeks (GW). METHODS: This cohort study was conducted from October 2020 to September 2021 among 28-36 GW preterm infants at the neonatal care unit of Jiangnan University Hospital. We divided this 12 month period into two consecutive 6 month periods. Composite iodine disinfectants and alcohol are used for skin and umbilical cord disinfection of preterm infants, respectively. Urinary iodine concentration (UIC), thyroid hormone levels, and neonatal behavioral and neurological assessment (NBNA) scores were determined in both groups. RESULTS: A total of 126 patients were included in the study, 65 in the iodine exposed group and 61 in the alcohol group. The second UIC and the incidence of serum T4≤5 µg/dL and TSH≥10 mIU/L in the iodine exposed group were significantly higher than those in the alcohol group (p<0.05). The first NBNA score was lower in the iodine exposed group than in the alcohol group (p<0.05). However, whether it has clinical significance remains to be explored. There was a linear relationship between the two NBNA scores (iodine exposure group, R 2=0.344; alcohol group, R 2=0.227). No sepsis or other adverse outcomes occurred in the two groups of preterm infants after disinfection with different disinfectants. CONCLUSIONS: Iodine-containing disinfectants seem to have the potential to cause an increased rate of thyroid dysfunction and a decreased neurological score and should be evaluated in further studies.