Plasmapheresis as a treatment of thyrotoxicosis in pregnancy: Case report

Abstract

Background/objective

A thyroid storm can manifest in many ways during gestation causing harm to the mother and to the baby and risking the outcome of the pregnancy.

Case report

A previously healthy female at 10 weeks gestational age presented to the hospital with complaints of nausea, vomiting and inability to tolerate diet. Patient was found to be in thyrotoxicosis. Propylthiouracil (PTU) could have been the first drug of choice since she was in her first trimester, however, could not be given due to her elevated hepatic function tests. Plasmapheresis was our only option to control her symptoms without risking her pregnancy. After a couple of sessions of plasmapheresis, the patient's thyroid and hepatic function tests resolved and she was put on PTU until her second trimester, when she was switched to methimazole.

Discussion

Current guidelines recommend the use of PTU in the first trimester of pregnancy due to the teratogenicity of methimazole, and consideration to switch to methimazole afterwards. However, when thionamides are contraindicated like in cases of elevated hepatic function tests, limited treatment options remain, especially in pregnancy. Data has shown that plasmapheresis can be performed relatively harmlessly in pregnant patients with severe thyrotoxicosis.

Conclusion

In rare situations where thionamides are contraindicated or ineffective, plasmapheresis is considered an effective treatment to reduce thyroid hormone levels but should be followed by definitive management.