Investigating Maternal Serum Thyroid Hormone, Beta-Human Chorionic Gonadotropin (Beta-HCG) and Free Beta-HCG Levels in Hyperemesis Gravidarum

Abstract

Objective: To investigate the influence of thyroid hormones, beta human chorionic gonadotropin (?-HCG), and free ?-HCG (f?-HCG) in the etiology of hyperemesis gravidarum (HG) and to determine the main hormone that is responsible for the exacerbation of symptoms. Materials and Methods: Serum thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), ?-HCG, and f?-HCG levels were measured twice (before and after hospitalization) in 55 patients with HG and measured once in 64 healthy controls. Serum hormone levels were determined using enzyme-linked immunosorbent assay. Results: Decreased mean TSH and increased mean fT4 levels were found in the pre-treatment serum samples of the HG group compared with the control group. Both differences were statistically significant (p=0.020 and p=0.007, respectively). However, there was no statistically significant difference in mean fT3, ?-HCG, and f?-HCG levels between the pre-treatment serum samples of the HG group and control group. We could not demonstrate any correlation between the levels of ?-HCG and thyroid hormones in the HG group; however, f?-HCG moderately correlated with fT4 levels (r=0.494). Conclusion: The presence of hyperthyroidism was observed as the leading alteration in HG. In this study, f?-HCG was demonstrated to have no direct effect on the etiology of HG; however, a possible indirect effect of f?-HCG in relation with thyroid hormones was indicated. Hyperthyroidism was assessed to be primarily responsible for the symptoms in HG.