Furthermore, multivariate regression analyses revealed that maternal serum selenium deficiency was a significant risk factor for the presence of anti-TPO antibodies (OR: 4.2, 95% CI: 1.0–16.7, P = 0.044, Supplementary Table 3), but not for parenchymal echogenicity on thyroid ultrasonography (OR: 2.1, 95% CI: 0.9–5.3, P = 0.103, Supplementary Table 3). The gene discussed is TPO; the disease is selenium deficiency.