High Body Mass Index Is an Indicator of Maternal Hypothyroidism, Hypothyroxinemia, and Thyroid-Peroxidase Antibody Positivity during Early Pregnancy.
BACKGROUND
Maternal thyroid dysfunction in early pregnancy may increase the risk of adverse pregnancy complications and neurocognitive deficiencies in the developing fetus. Currently, some researchers demonstrated that body mass index (BMI) is associated with thyroid function in nonpregnant population. Hence, the American Thyroid Association recommended screening thyroid function in obese pregnant women; however, the evidence for this is weak. For this purpose, our study investigated the relationship between high BMI and thyroid functions during early pregnancy in Liaoning province, an iodine-sufficient region of China.


METHODS
Serum thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroid-peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb) concentration, urinary iodine concentration (UIC), and BMI were determined in 6303 pregnant women.


RESULTS
BMI ≥ 25 kg/m(2) may act as an indicator of hypothyroxinemia and TPOAb positivity and BMI ≥ 30 kg/m(2) was associated with increases in the odds of hypothyroidism, hypothyroxinemia, and TPOAb positivity. The prevalence of isolated hypothyroxinemia increased among pregnant women with BMI > 24 kg/m(2).


CONCLUSIONS
High BMI during early pregnancy may be an indicator of maternal thyroid dysfunction; for Asian women whose BMI > 24 kg/m(2) and who are within 8 weeks of pregnancy, thyroid functions should be assessed especially.
Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang, Liaoning 110001, China.
Cheng
C
Han
Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang, Liaoning 110001, China.
Chenyan
C
Li
Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang, Liaoning 110001, China.
Jinyuan
J
Mao
Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang, Liaoning 110001, China.
Weiwei
W
Wang
Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang, Liaoning 110001, China.
Xiaochen
X
Xie
Shenyang Women's and Children's Hospital, No. 87 Danan Street, Shenyang, Liaoning 110001, China.
Weiwei
W
Zhou
Shenyang Women's and Children's Hospital, No. 87 Danan Street, Shenyang, Liaoning 110001, China.
Chenyang
C
Li
Department of Obstetrics and Gynecology, No. 202 Hospital of People's Liberation Army, No. 5 Guangrong Street, Shenyang, Liaoning 110001, China.
Bin
B
Xu
Dalian Obstetrics and Gynecology Hospital, No. 1 Dunhuang Street, Dalian, Liaoning 116001, China.
Lihua
L
Bi
Department of Obstetrics and Gynecology, The First Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang, Liaoning 110001, China.
Tao
T
Meng
Department of Endocrinology, The First Affiliated Hospital of Dalian Medical University, No. 222 Zhongshan Road, Dalian, Liaoning 116001, China.
Jianling
J
Du
Department of Endocrinology, No. 202 Hospital of People's Liberation Army, No. 5 Guangrong Street, Shenyang 110001, China.
Shaowei
S
Zhang
Department of Endocrinology, Dalian Municipal Central Hospital, Dalian Medical University, No. 826 Xinan Road, Dalian, Liaoning 116001, China.
Zhengnan
Z
Gao
Department of Endocrinology, The First Hospital of Dandong, No. 76 Baoshan Street, Dandong, Liaoning 118001, China.
Xiaomei
X
Zhang
Shenyang Women and Children Health Care Center, No. 74 Chongshan East Street, Shenyang, Liaoning 110001, China.
Liu
L
Yang
Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang, Liaoning 110001, China.
Chenling
C
Fan
Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang, Liaoning 110001, China.
Weiping
W
Teng
Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang, Liaoning 110001, China.
Zhongyan
Z
Shan
D001323:Autoantibodies / Q000097:blood; D015992:Body Mass Index; D002681:China; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000503:physiopathology*; D007453:Iodide Peroxidase / Q000276:immunology*; D007455:Iodine / Q000652:urine; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D013960:Thyroid Function Tests / Q000379:methods; D013961:Thyroid Gland / Q000503:physiopathology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D001323:Autoantibodies; C006606:anti-thyroglobulin; C056626:thyroid microsomal antibodies; D013972:Thyrotropin; D007455:Iodine; D007453:Iodide Peroxidase; D013974:Thyroxine