title: Low Thyroid Hormone in Early Pregnancy Is Associated With an Increased Risk of Gestational Diabetes Mellitus.
abstract: Although thyroid dysfunction in early pregnancy may have adverse effects on pregnancy outcome and offspring, few prospective studies have evaluated these effects.
  
  
  
  Our aim was to evaluate the correlations between different thyroid hormone levels in early pregnancy and the incidence of gestational diabetes mellitus (GDM).
  
  
  
  The study comprised 27 513 mothers who provided early pregnancy serum samples for analyses of thyroid function. GDM was diagnosed using a 2 hours, 75-g oral glucose tolerance test, and the mothers were grouped and compared according to the results.
  
  
  
  We focused on GDM during the index pregnancy.
  
  
  
  The incidence of GDM in pregnant women tended to increase with age (5.83%, 10.18%, 14.95%, and 22.40%; P < .0001). The incidence of GDM increased with increasing prepregnancy body mass index (P < .0001). Pregnant women with a family history of diabetes had a much higher incidence of GDM than those without a family history of diabetes (21.09% vs 12.92%; P < .0001). The level of free T4(FT4) in early pregnancy in GDM women was lower than that in non GDM women (P < .0001). With increasing early pregnancy FT4, the rate of incident GDM was decreasing (P < .0001).
  
  
  
  Low thyroid hormone levels in early pregnancy are a risk factor for GDM incidence.
authors: International Peace Maternity and Child Health Hospital (S.Y., F.-T.S., H.-F.H., J.F.), School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China; Institute of Embryo-Fetal Original Adult Disease Affiliated to Shanghai Jiao Tong University School of Medicine (F.-T.S., H.-F.H.), Shanghai 200030, China; and Department of Obstetrics and Gynaecology (P.C.K.L.), Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada V6H 3V5.
authors: Shuai
authors: S
authors: Yang
authors: International Peace Maternity and Child Health Hospital (S.Y., F.-T.S., H.-F.H., J.F.), School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China; Institute of Embryo-Fetal Original Adult Disease Affiliated to Shanghai Jiao Tong University School of Medicine (F.-T.S., H.-F.H.), Shanghai 200030, China; and Department of Obstetrics and Gynaecology (P.C.K.L.), Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada V6H 3V5.
authors: Feng-Tao
authors: FT
authors: Shi
authors: International Peace Maternity and Child Health Hospital (S.Y., F.-T.S., H.-F.H., J.F.), School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China; Institute of Embryo-Fetal Original Adult Disease Affiliated to Shanghai Jiao Tong University School of Medicine (F.-T.S., H.-F.H.), Shanghai 200030, China; and Department of Obstetrics and Gynaecology (P.C.K.L.), Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada V6H 3V5.
authors: Peter C K
authors: PC
authors: Leung
authors: International Peace Maternity and Child Health Hospital (S.Y., F.-T.S., H.-F.H., J.F.), School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China; Institute of Embryo-Fetal Original Adult Disease Affiliated to Shanghai Jiao Tong University School of Medicine (F.-T.S., H.-F.H.), Shanghai 200030, China; and Department of Obstetrics and Gynaecology (P.C.K.L.), Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada V6H 3V5.
authors: He-Feng
authors: HF
authors: Huang
authors: International Peace Maternity and Child Health Hospital (S.Y., F.-T.S., H.-F.H., J.F.), School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China; Institute of Embryo-Fetal Original Adult Disease Affiliated to Shanghai Jiao Tong University School of Medicine (F.-T.S., H.-F.H.), Shanghai 200030, China; and Department of Obstetrics and Gynaecology (P.C.K.L.), Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada V6H 3V5.
authors: Jianxia
authors: J
authors: Fan
mesh_terms: D000328:Adult; D002681:China / Q000453:epidemiology; D003918:Dextrothyroxine / Q000097:blood*; D016640:Diabetes, Gestational / Q000097:blood* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012306:Risk; D055815:Young Adult
chemical_list: D003918:Dextrothyroxine