title: Risk factors for congenital hypothyroidism: results of a population case-control study (1997-2003).
abstract: OBJECTIVE
  To identify risk factors for permanent and transient congenital hypothyroidism (CH).
  
  
  METHODS
  A population-based case-control study was carried out by using the network created in Italy for the National Register of Infants with CH.
  
  
  METHODS
  Four controls were enrolled for each new CH infant; 173 cases and 690 controls were enrolled in 4 years. In order to distinguish among risk factors for permanent and transient CH, diagnosis was re-evaluated 3 years after enrollment when there was a suspicion of transient CH being present. Familial, maternal, neonatal and environmental influences were investigated.
  
  
  RESULTS
  An increased risk for permanent CH was detected in twins by a multivariate analysis (odds ratio (OR) = 12.2, 95% confidence interval (CI): 2.4-62.3). A statistically significant association with additional birth defects, female gender and gestational age >40 weeks was also confirmed. Although not significant, an increased risk of CH was observed among infants with a family history of thyroid diseases among parents (OR = 1.9, 95% CI: 0.7-5.2). Maternal diabetes was also found to be slightly associated with permanent CH (OR = 15.7, 95% CI: 0.9-523) in infants who were large for gestational age. With regard to transient CH, intrauterine growth retardation and preterm delivery were independent risk factors for this form of CH.
  
  
  CONCLUSIONS
  This study showed that many risk factors contribute to the aetiology of CH. In particular, our results suggested a multifactorial origin of CH in which genetic and environmental factors play a role in the development of the disease.
authors.affiliation: Centro Nazionale di Epidemiologia, Sorveglianza e Promozione della Salute, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Medda
authors.forename: Antonella
authors.initials: A
authors.lastname: Olivieri
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Stazi
authors.forename: Michele E
authors.initials: ME
authors.lastname: Grandolfo
authors.forename: Cristina
authors.initials: C
authors.lastname: Fazzini
authors.forename: Mariangiola
authors.initials: M
authors.lastname: Baserga
authors.forename: Massimo
authors.initials: M
authors.lastname: Burroni
authors.forename: Emanuele
authors.initials: E
authors.lastname: Cacciari
authors.forename: Francesca
authors.initials: F
authors.lastname: Calaciura
authors.forename: Alessandra
authors.initials: A
authors.lastname: Cassio
authors.forename: Luca
authors.initials: L
authors.lastname: Chiovato
authors.forename: Pietro
authors.initials: P
authors.lastname: Costa
authors.forename: Daniela
authors.initials: D
authors.lastname: Leonardi
authors.forename: Maria
authors.initials: M
authors.lastname: Martucci
authors.forename: Lidia
authors.initials: L
authors.lastname: Moschini
authors.forename: Severo
authors.initials: S
authors.lastname: Pagliardini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Parlato
authors.forename: Alberto
authors.initials: A
authors.lastname: Pignero
authors.forename: Aldo
authors.initials: A
authors.lastname: Pinchera
authors.forename: Danielle
authors.initials: D
authors.lastname: Sala
authors.forename: Lidia
authors.initials: L
authors.lastname: Sava
authors.forename: Vera
authors.initials: V
authors.lastname: Stoppioni
authors.forename: Francesco
authors.initials: F
authors.lastname: Tancredi
authors.forename: Fabiola
authors.initials: F
authors.lastname: Valentini
authors.forename: Riccardo
authors.initials: R
authors.lastname: Vigneri
authors.forename: Mariella
authors.initials: M
authors.lastname: Sorcini
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002675:Child, Preschool; D003409:Congenital Hypothyroidism / Q000209:etiology*; D004200:Diseases in Twins; D004777:Environment; D005260:Female; D005317:Fetal Growth Retardation; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007455:Iodine / Q000172:deficiency; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D011254:Pregnancy in Diabetics; D012307:Risk Factors
chemical_list: D007455:Iodine