In line with our study, many previous studies also identified DNA methylation changes of genes related to metabolism in PTB cord blood [29, 30, 52], such as NCOR2, IGF2BP1, IGF2, and TET1. Additionally, we also observed DNA methylation alterations of BAIAP2 and OXTR in sPTB cord blood, which were related to neurodevelopmental disorders. This evidence concerns the gene TET1 and neurodevelopmental disorder.