Thyroid Hormone in Hyperemesis Gravidarum

Chang, Jeon Ho; Kim, Gi Hwan; Kim, Hyeoung Woo; Jun, Hyun Ah; Lee, Kyung Hee; Park, Man Chul; Lee, Yong Woo

Abstract

Nausea and vomiting during early pregnancy is a common phenomenon, but very little data is available about the mechanism of this condition, and the etiology of hypereme sis is still unknown. One of the most popular hypothesis is that abnormal hormone levels, especi-ally thyroid hormone, may be possible etiologic factor of nausea and vomiting. The object of this study is to investigate the relationship between the presence or ab- sence of nausea and vomiting in early pregnancy and thyroid function. Twenty patients suffering from hyperemesis gravidarum of first trimester of pregnancy and twenty from morning sickness were selected. 20 non-pregnant and 20 pregnant women without nausea and vomiting were selected to age-matched control groups. Thyroid function was evaluated by using T3, T4, and TSH radioimmunoassay. Comparison between groups were analyzed with the paired t-test. In this study, we found that a significant increase in serum total T4(p<0.001) and T3 (p<0.05), and a significant decrease in serum TSH(p<0.001) were observed in pregnancy with hyperemesis gravidarum relative to the level in normal pregnancy. These results were correlated with the severity of nausea and vomiting. In conclusion, highly elevated T3 and T4 were closely linked to the cause of the vomi- ting in pregnancy with hyperemesis gravidarum. Further study is needed to evaluate more clearly the thyroid status of patients with hyperemesis gravidarum and to seek a therapy.