Lipid Metabolism in Pregnancy Women with Hypothyroidism and Potential Influence on Pregnancy Outcome

Abstract

Thyroid hormone (TH) is essential for maintaining normal physiological processes during pregnancy, including the metabolism of energy materials in both the mother and fetus and the growth and development of fetal bone and nervous system. TH can act on the liver, fat, and other tissues and organs to participate in lipid synthesis and breakdown through multiple pathways. Consequently, abnormal thyroid function is often accompanied by lipid metabolism disorders. Both clinical and subclinical hypothyroidism, as well as dyslipidemia during pregnancy, have been shown to be associated with an increased risk of multiple adverse pregnancy outcomes. Recently, there has been an increased interest in studying the alteration of lipidomic and hypothyroidism (both clinical and subclinical hypothyroidism) during pregnancy. Studies have suggested that altered lipid molecules might be used as potential biomarker and associated with adverse maternal and neonatal outcome. Thus, we summarized the associations between lipid metabolism and clinical or subclinical hypothyroidism during pregnancy in this review. Then, we discussed the underlying mechanisms of thyroid dysfunction and lipid metabolism. In addition, we reviewed the possible effect of dyslipidemia on pregnancy and neonatal outcome. However, the relationship between hypothyroidism during pregnancy and changes in the lipid profile and how to intervene in the occurrence and development of adverse pregnancy outcomes require further study.

Figure 1

The scheme outlines the physical action of thyroid hormones on lipid metabolism during pregnancy. FFA: free fatty acid; hCG: human chorionic gonadotropin.

Figure 2

The comparison of lipid changes in healthy pregnant women and pregnant with thyroid disease. CH: clinical hypothyroidism; SCH: subclinical hypothyroidism; TSH: thyroid-stimulating hormone; FT4: free thyroxine; SREBP: sterol regulatory element-binding protein; FGF: fibroblast growth factor; PCSK9: proprotein convertase subtilisin 9; TC: total cholesterol; TGs: triglycerides; HDL-c: high-density lipoprotein cholesterol; Apo-A1: apolipoprotein A1; Apo-B: apolipoprotein B; LDL-c: low-density lipoprotein cholesterol; VLDL: very low-density lipoprotein; Th17 cells: T helper 17 cells; Treg cells: regulatory T cells.