Associations of Thyroid Function Tests with Lipid Levels and Adverse Pregnancy Outcomes During the First Trimester

Wen-Yu Liu,1,* Yu-Ting Zhu,2,* Xian-Ming Xu,1 Jia-Rong Zhang,3 Xu-Pei Gan,1 De-Cui Cheng,1 Feng Lu,4 Cong Lu1 1Department of Obstetrics and Gynecology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 201600, People’s Republic of China; 2Department of Gynecology Maternal and Child Health Hospital of Jiading District, Shanghai, 201800, People’s Republic of China; 3Department of Obstetrics and Gynecology, Zhongshan Hospital, Fudan University, Shanghai, 200030, People’s Republic of China; 4Department of Obstetrics and Gynecology, Songjiang Maternal and Child Health-Care Hospital, Shanghai, 201600, People’s Republic of China*These authors contributed equally to this workCorrespondence: Cong Lu, Department of Obstetrics and Gynecology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 650 of Xinsongjiang Road, Songjiang District, Shanghai, 201600, People’s Republic of China, Tel +86-021-37798537, Email lucongtr5@163.com Feng Lu, Department of Obstetrics and Gynecology, Songjiang Maternal and Child Health-Care Hospital, No. 1010 of Xilin North Road, Songjiang District, Shanghai, 201600, People’s Republic of China, Tel +86-18918282005, Email rlufengni@163.comObjective: The present study aims to evaluate the relationship of thyroid function during the first trimester of pregnancy with lipid levels and pregnancy outcomes.Methods: Women who delivered babies at the Shanghai General Hospital between March 2019 and December 2019 with a known pregnancy outcome and complete data were included in the present study (n = 1779). A retrospective cohort study of all subjects with available first-trimester thyroid function testing and lipid levels data was conducted, and the relationship of thyroid function with lipid levels and pregnancy outcomes was evaluated. The data were analyzed using the SPSS software for statistical correlation.Results: The proportion of caesarean sections was higher in women with hypothyroxinemia (HIA) and hypothyroidism than in women with euthyroidism. Hypothyroidism was shown to be related with polyhydramnios, preterm labor and hypertriglyceridemia. HIA was correlated with increased rates of gestational diabetes mellitus (GDM), preeclampsia, gestational hypertension and hypertriglyceridemia. Compared with the euthyroidism group, the hypothyroidism group had a higher apolipoprotein A1 (Apo A1) level and apolipoprotein B level; the subclinical hypothyroidism group had a higher total cholesterol (TC) level and low-density lipoprotein cholesterol level; the HIA group had higher triglyceride, high-density lipoprotein cholesterol levels and lower TC, Apo A1 levels. TC levels were positively correlated with the thyroid-stimulating hormone level and negatively correlated with free thyroxine (FT4) level, and free triiodothyronine and FT4 levels were positively correlated with GDM occurrence.Conclusion: Thyroid function in early pregnancy is associated with dyslipidemia and pregnancy outcomes; conventional screening of thyroid diseases in early pregnancy may help improve lipid levels and decrease adverse pregnancy outcomes.Keywords: first trimester, thyroid function tests, adverse pregnancy outcome, dyslipidemia