A Case of Transient Gestational Hyperthyroidism Complicated With Acute Liver Injury Successfully Treated With Plasma Exchange.

Therapeutic Plasma Exchange (TPE) in pregnancy is rare due to the uncertainty of efficiency and safety in clinical practice. It is experience-based on extrapolation of efficacy and safety in non-pregnant populations than evidence-based. We reported a case of severe refractory hyperemesis gravidarum secondary to transient gestational hyperthyroidism in a first-trimester pregnancy, which was complicated by acute hepatic injury during the clinical course and successfully managed with TPE. Both the clinical picture and objective index were improved dramatically after plasma exchanges. Three sessions of plasma exchange provided a 61% decrease in serum FT4 (free thyroxine) concentration (4.34 ng/dL to 1.71 ng/dL) and 89% decrease in alanine aminotransferase (ALT) (647 units/L to 69 units/L). The patient's symptoms improved significantly after TPE. In two weeks follow-up visit, her thyroid function was in the recommended range of 1st-trimester pregnancy (1.06 ng/dL) and her liver function was normalized (ALT 15 units/L, aspartate aminotransferase {AST} 11 units/L). In conclusion, plasma exchange may be used as an alternative therapeutic option in pregnancy to manage transient hyperthyroidism who failed or was unable to tolerate or have contradictions to antithyroid medications and thyroidectomy. Our case provides evidence of TPE in the treatment of thyrotoxicosis in pregnancy.