Hypothyroidism in pregnancy

- More common in pregnant women than hyperthyroidism.
- Incidence - 9 (White) and 3 (Black) per 1000 pregnant women. 

- Commonest cause - auto-immune (idiopathic), including Hashimoto's thyroiditis. 

- Associated with thyroid microsomal antibodies.
- Anti-thyroid antibodies may cause neonatal hypothyroidism