Aetiology of true congenital hypothyroidism for period 2, before the introduction of dual scanning (pre-1999) in the West of Scotland and after the introduction of dual scanning (from January 1999)
| Aetiology | 1994–1998 | Aetiology scanned | 1999–2003 | Aetiology scanned | Whole cohort |
|---|---|---|---|---|---|
| ’94–’98 | ’99–’03 | 1994–2003 | |||
| *Two instances of isoimmune thyroiditis and one instance of maternal radioiodine administration. | |||||
| All | 77 (100%) | 23.4% | 84 (100%) | 77.4% | 161 (100%) |
| Unknown | 52 (67.5%) | 11.5% | 20 (23.8%) | 25% | 72 (44.7%) |
| Ectopia | 4 (5.2%) | 75% | 22 (26.2%) | 100% | 26 (16.2%) |
| Athyreosis | 5 (6.5%) | 60% | 18 (21.4%) | 100% | 23 (14.3%) |
| Hypoplasia | 1 (1.3%) | 100% | 8 (9.5%) | 87.5% | 9 (5.6%) |
| Dyshormonogenesis | 9 (11.7%) | 55.5% | 12 (14.3%) | 100% | 21 (13.0%) |
| Other cause* | 2 (2.6%) | 0% | 1 (1.2%) | 100% | 3 (1.9%) |
| Insufficient data | 4 (5.2%) | – | 3 (3.6%) | 66.7% | 7 (4.3%) |