Graves’ hyperthyroidism is associated with significant obstetric, maternal, fetal, and neonatal complications. Early diagnosis and an understanding of the management of Graves’ hyperthyroidism in pregnancy can help to prevent these complications. Antithyroid drugs (ATD) should be avoided in early pregnancy, given their association with congenital malformations.
TSH-receptor antibodies (TRAb) are integral in the management of Graves’ hyperthyroidism in pregnancy and in the preconception period. TRAb are indicative of the current activity of Graves’ hyperthyroidism and the likelihood of relapse. Furthermore, TRAb predicts the risk of fetal and neonatal hyperthyroidism.
The incidence of congenital malformations is roughly the same for propylthiouracil (PTU) and methimazole (MMZ). Exposure to both ATDs in early pregnancy has been associated with increased incidence of congenital malformations compared with exposure to either ATD alone.
The goal of the physician is maintaining euthyroidism throughout pregnancy and delivery of a healthy, euthyroid baby. An understanding of the natural progression of Graves’ hyperthyroidism in pregnancy and the proper utilization of TRAb enables the physician to minimize the risks associated with Graves’ hyperthyroidism and side effects of ATDs unique to pregnancy. The physician should prioritize preconception counseling in women with Graves’ hyperthyroidism in order to avoid hyperthyroidism and having to use ATDs in pregnancy.
Division of Endocrinology, Diabetes, & Metabolism, Department of Medicine and Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
Correspondence to Caroline T. Nguyen, MD, Assistant Professor of Clinical Medicine, Obstetrics, and Gynecology, Division of Endocrinology, Diabetes, & Metabolism, Department of Medicine and Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, 1540 Alcazar Street - CHP 204B, Los Angeles, CA 90033, USA. E-mail: Caroline.Nguyen@med.usc.edu