The regional cohort (n = 14,573) included the biochemical measurement of thyroid stimulating hormone (TSH), thyroid peroxidase antibodies (TPO-Ab), and thyroglobulin antibodies (Tg-Ab) (ADVIA Centaur XPT, Siemens Healthineers) among pregnant women in The North Denmark Region from 2011–2015 who had a blood sample drawn in early pregnancy as part of routine prenatal screening for chromosomal anomalies. Here, TPO is linked to Chromosomal anomaly.