Postpartum thyroiditis

Postpartum thyroiditis
Specialty	Obstetrics

Postpartum thyroiditis refers to thyroid dysfunction occurring in the first 12 months after pregnancy^[1] and may involve hyperthyroidism, hypothyroidism or the two sequentially. According to the National Institute of Health, postpartum thyroiditis affects about 8% of pregnancies.^[2] There are, however, different rates reported globally. This is likely due to the differing amounts of average postpartum follow times around the world, and due to humans' own innate differences. For example, in Bangkok, Thailand the rate is 1.1%, but in Brazil it is 13.3%.^[2] The first phase is typically hyperthyroidism. Then, the thyroid either returns to normal or a woman develops hypothyroidism. Of those women who experience hypothyroidism associated with postpartum thyroiditis, one in five will develop permanent hypothyroidism requiring lifelong treatment.

Postpartum thyroiditis is believed to result from the modifications to the immune system necessary in pregnancy, and histologically is a subacute lymphocytic thyroiditis. The process is normally self-limiting, but when conventional antibodies are found there is a high chance of this proceeding to permanent hypothyroidism. Postpartum thyroiditis is a member of the group of thyroiditis conditions known as resolving thyroiditis.