title: Gestational hypothyroidism: development of mild hypothyroidism in early pregnancy in previously euthyroid women.
abstract: OBJECTIVE
  To determine the proportion of euthyroid women attending a fertility practice who develop hypothyroidism in very early pregnancy (gestational hypothyroidism [GHT]), and to examine the association of GHT with exogenous gonadotropin treatment.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  A private reproductive medicine practice.
  
  
  METHODS
  All healthy women (N = 94) with infertility or recurrent pregnancy loss, TSH level <2.5 mIU/L, negative thyroid peroxidase antibodies at initial evaluation, and not taking thyroid medication, who conceived during an 18-month period.
  
  
  METHODS
  Usual fertility care; 30 women who had received exogenous gonadotropins.
  
  
  METHODS
  Serum TSH level at the time of pregnancy detection.
  
  
  RESULTS
  Gestational hypothyroidism (TSH ≥ 2.5 mIU/L) developed in 23 of 94 women (24%). The mean increase in serum TSH level from initial evaluation to early pregnancy was 0.45 ± 0.08 [SE] mIU/L. There was a trend toward the association of GHT with use of exogenous gonadotropins. Gestational hypothyroidism was positively associated with initial prepregnancy TSH level.
  
  
  CONCLUSIONS
  Euthyroid women may develop mild hypothyroidism in early pregnancy, especially after exogenous gonadotropin treatment. Appropriate vigilance will allow for timely levothyroxine treatment.
authors.affiliation: Alabama Fertility Specialists, Birmingham, Alabama. Electronic address: karenhammond@bellsouth.net.
authors.forename: Karen R
authors.initials: KR
authors.lastname: Hammond
authors.affiliation: Alabama Fertility Specialists, Birmingham, Alabama.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Cataldo
authors.affiliation: Alabama Fertility Specialists, Birmingham, Alabama.
authors.forename: Janice A
authors.initials: JA
authors.lastname: Hubbard
authors.affiliation: Alabama Fertility Specialists, Birmingham, Alabama.
authors.forename: Beth A
authors.initials: BA
authors.lastname: Malizia
authors.affiliation: Alabama Fertility Specialists, Birmingham, Alabama.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Steinkampf
mesh_terms: D000026:Abortion, Habitual / Q000097:blood / Q000453:epidemiology; D000328:Adult; D000407:Alabama / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D015984:Causality; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006062:Gonadotropins / Q000627:therapeutic use*; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000453:epidemiology*; D015994:Incidence; D007247:Infertility, Female / Q000097:blood / Q000188:drug therapy* / Q000453:epidemiology*; D010062:Ovulation Induction / Q000706:statistics & numerical data*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000453:epidemiology*; D012016:Reference Values; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013972:Thyrotropin / Q000097:blood
chemical_list: D015415:Biomarkers; D006062:Gonadotropins; D013972:Thyrotropin
keywords: Hypothyroidism; gonadotropins; infertility; pregnancy; spontaneous abortion