SAT-588 Unique Presentation of Postpartum Thyroiditis with Features of Graves' Disease

Introduction - Postpartum thyroiditis (PPT) is a rare medical condition occurring after pregnancy. Postpartum thyroiditis is a syndrome of transient or permanent thyroid dysfunction occurring in the first year after delivery. It can present as clinical thyrotoxicosis, followed by hypothyroidism and subsequent recovery of thyroid function or it may present as an isolated thyrotoxicosis or hypothyroidism. An estimated 20-40% of women develop permanent hypothyroidism; usually during the 3 to 10 year interval following an episode of PPT. PPT is the most common thyroid disease in the postpartum period with an incidence between 5-9%. The condition is most common in patients with positive thyroid antibodies (TPO), type 1 diabetes or prior history of PPT. We present a unique case of postpartum thyroiditis with postpartum hyperthyroidism, with markers of Graves’ disease, in a patient with a maternal history of Graves’ disease. Case description - An 18 year old female, without prior medical history, presented with thyrotoxicosis following delivery of her first child. Initially, she responded to therapy with propranolol; however, when her thyroid function became increasingly symptomatic, therapy was augmented with methimazole. Methimazole was selected because of the corresponding clinical features of Graves’ disease coupled with a positive thyroid stimulating immunoglobulin (TSI = 431) and family history of Graves’ disease. Thyroid scan and uptake showed homogenous thyroid without discrete nodule with normal thyroid uptake. Unfortunately, methimazole precipitated urticaria and pruritus, without any liver abnormalities, necessitating its’ discontinuance. Propranolol monotherapy subsequently provided effective symptomatic relief. The patient’s thyroid levels eventually peaked following delivery (fT4 -4.32) before trending downward (fT4 = 1.79), paralleling the resolution of her symptomatic biochemical thyrotoxicosis and resolution of her goiter. Conclusion - Literature review revealed lack of similar case report. Our patient benefitted from symptomatic therapy with propranolol. Women with preexisting thyroid disorders are at high risk for developing postpartum thyroiditis and should be closely monitored for one year post-partum. We hypothesize that our patient most likely had preexisting Grave’s disease that was exacerbated after her delivery. Reference - Pearce EN. Thyroid disorders during pregnancy and postpartum. Best Pract Res Clin Obstet Gynaecol. 2015;29(5); 700-706.