title: Does the thyroid-stimulating hormone measured concurrently with first trimester biochemical screening tests predict adverse pregnancy outcomes occurring after 20 weeks gestation?
abstract: BACKGROUND
  Maternal hypothyroidism in early pregnancy is associated with adverse outcomes, but not consistently across studies. First trimester screening for chromosomal anomalies is routine in many centers and provides an opportunity to test thyroid function.
  
  
  OBJECTIVE
  To determine if thyroid function tests performed with first trimester screening predicts adverse pregnancy outcomes.
  
  
  METHODS
  A cohort study of 2411 women in Western Australia with singleton pregnancies attending first trimester screening between 9 and 14 weeks gestation.
  
  
  METHODS
  We evaluated the association between TSH, free T4, free T3, thyroid antibodies, free beta human chorionic gonadotrophin (β-hCG) and pregnancy associated plasma protein A (PAPP-A) with a composite of adverse pregnancy events as the primary outcome. Secondary outcomes included placenta previa, placental abruption, pre-eclampsia, pregnancy loss after 20 weeks gestation, threatened preterm labor, preterm birth, small size for gestational age, neonatal death, and birth defects.
  
  
  RESULTS
  TSH exceeded the 97.5th percentile for the first trimester (2.15 mU/L) in 133 (5.5%) women, including 22 (1%) with TSH above the nonpregnant reference range (4 mU/L) and 5 (0.2%) above 10 mU/L. Adverse outcomes occurred in 327 women (15%). TSH and free T4 did not differ significantly between women with or without adverse pregnancy events. On the multivariate analysis, neither maternal TSH >2.15 mU/L nor TSH as a continuous variable predicted primary or secondary outcomes.
  
  
  CONCLUSIONS
  Testing maternal TSH as part of first trimester screening does not predict adverse pregnancy outcomes. This may be because in the community setting, mainly mild abnormalities in thyroid function are detected.
authors.affiliation: Department of Endocrinology and Diabetes (G.S.Y.O., S.J.B., E.M.L., J.P.W.) and Department of General Medicine (G.S.Y.O.), Sir Charles Gairdner Hospital, Nedlands 6009 Australia; Department of Clinical Biochemistry (N.C.H., E.M.L.), PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands 6009 Australia; and School of Medicine and Pharmacology (J.P.W.), The University of Western Australia, Crawley 6009 Australia.
authors.forename: Gregory S Y
authors.initials: GS
authors.lastname: Ong
authors.forename: Narelle C
authors.initials: NC
authors.lastname: Hadlow
authors.forename: Suzanne J
authors.initials: SJ
authors.lastname: Brown
authors.forename: Ee Mun
authors.initials: EM
authors.lastname: Lim
authors.forename: John P
authors.initials: JP
authors.lastname: Walsh
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000175:diagnosis*; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D013960:Thyroid Function Tests; D013963:Thyroid Hormones / Q000097:blood; D013972:Thyrotropin / Q000097:blood*
chemical_list: D006063:Chorionic Gonadotropin; D013963:Thyroid Hormones; D013972:Thyrotropin