Low neonatal serum BDNF levels have been associated with impaired neurodevelopment (Dingsdale et al. 2022; Skogstrand et al. 2019; Yu et al. 2016), i.e., in cases with neurodevelopmental disorders (e.g., autism), lower BDNF serum levels have been found in umbilical cord serum than in healthy controls (Skogstrand et al. 2019; Yu et al. 2016). Here, BDNF is linked to autism.