Results: We identified 23 CpGs (genome-wide p level: 1.06 × 10−7) that were associated with maternal smoking during pregnancy, including associated genes AHRR (cancer development), FTO (obesity), CNTNAP2 (developmental processes), CYP1A1 (detoxification), MYO1G (cell signalling), and FRMD4A (nicotine dependence). Here, CNTNAP2 is linked to cancer.