Postpartum Thyroiditis

Postpartum thyroiditis (PPT) is a destructive autoimmune disease occurring in the first year after delivery in women without a history of thyroid disease prior to pregnancy. Postpartum thyroiditis could cause transient or permanent thyroid disease. Three clinical presentations have been suggested for postpartum thyroiditis are as follows: (1) transient hyperthyroidism (32% of patients), (2) transient hypothyroidism (43% of patients), and (3) transient hyperthyroidism followed by hypothyroidism and then recovery, which is the classic form of PPT (25% of patients). Postpartum thyroiditis is an autoimmune disease and associated with the presence of antibodies to thyroid peroxidase (TPO). Chances of developing postpartum thyroiditis in pregnant women who have positive TPO antibodies early in pregnancy are 30% to 52%. Postpartum thyroiditis could occur after the loss of a pregnancy at 5 to 20 weeks gestation. During pregnancy level of TPO antibodies naturally decreases due to the immunosuppressed state of pregnancy. Women who remain positive for TPO antibodies in the third trimesters of pregnancy will have an 80% chance of developing postpartum thyroiditis. Screening of high-risk women for developing postpartum thyroiditis, such as a positive test for antithyroid peroxidase antibody, history of postpartum thyroiditis, type 1 diabetes mellitus, is recommended by Endocrine Society clinical guidelines. High-risk women should be evaluated for serum TSH levels at three and six months postpartum.