Establishment of reference range for thyroid hormones in normal pregnant women in China's coastal area.
OBJECTIVE
The current study aims to establish reference ranges for thyroid hormones in normal pregnant women during their pregnancy period.


METHODS
A one-time cross-sectional survey was conducted on 490 normal pregnant women and 51 nonpregnant women (control). The serum thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free tetraiodothyronine (FT4) levels were measured.


RESULTS
The serum FT3 and FT4 levels in pregnant women decreased gradually from the first to the last three months of pregnancy (p < 0.01). The serum TSH level increased gradually during the whole pregnancy (p < 0.01), and was significantly lower than the control (p < 0.01) in the first three months. However, in the middle and last three months of pregnancy, TSH was higher than the control (p < 0.01).


CONCLUSIONS
The thyroid hormone levels in normal pregnant women are different from those in non-pregnant women; significant differences exist among the three stages of pregnancy.
J
J
Zha
D
D
Ming
Y
Y
Jiang
C
C
Huang
T
T
Jiang
C
C
Chen
R
R
Lin
W
W
Su
S
S
Gu
D000328:Adult; D001323:Autoantibodies / Q000097:blood; D016022:Case-Control Studies; D002681:China; D006063:Chorionic Gonadotropin / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D011247:Pregnancy / Q000097:blood*; D011264:Pregnancy Trimesters / Q000097:blood; D012016:Reference Values; D013963:Thyroid Hormones / Q000097:blood*; D055815:Young Adult
D001323:Autoantibodies; D006063:Chorionic Gonadotropin; D013963:Thyroid Hormones; D007453:Iodide Peroxidase