Thyroid dysgenesis thyroid gland may be located anywhere along the path of the descent of the thyroid during its embryological development, although it is most commonly located at the base of the tongue, just posterior to the foramen cecum of the tongue. In this location, an aberrant or ectopic thyroid gland is known as a "lingual thyroid". If the thyroid fails to descend to even higher degree, then the resulting final resting point of the thyroid gland may be high in the neck, such as just below the hyoid bone. Parts of ectopic thyroid tissue ("accessory thyroid tissue") can also occur, and
Thyroid disease in pregnancy of thyroid disease e.g. women with a personal or family history of thyroid disease, goitre, or co-existing primary autoimmune disorder like type 1 diabetes. Hypothyroidism is diagnosed by noting a high TSH associated with a subnormal T4 concentration. Subclinical hypothyroidism (SCH) is present when the TSH is high but the T4 level is in the normal range but usually low normal. SCH is the commonest form of hypothyroidism in pregnancy and is usually due to progressive thyroid destruction due to autoimmune thyroid disease. Several studies, mostly retrospective, have shown an association between overt hypothyroidism and adverse fetal and obstetric outcomes