title: Phenotypic characterization and risk factors for microtia in East China, a case-control study.
abstract: OBJECTIVE
  Although congenital microtia has been reported in various studies, little is known about the etiology of isolated and sporadic cases. The aim was to analyze potential risk factors for isolated and sporadic microtia using case-control study in East China.
  
  
  METHODS
  The study analyzed data from the hospital-based recruitment for deliveries between 2007 and 2013. Nine hundred eleven patients with microtia enrolled in the phenotypic characterization analysis, and then were adjusted by sex, age, region, syndrome and family history to compare with 562 random normal controls for potential risk factors.
  
  
  RESULTS
  Microtia is observed more often in males (69.7%), and the cases were typically unilateral (74.0%), right-sided (57.2%), sporadic (92.0%) and isolated (69.5%). Mothers of children with microtia were more likely to have suffered a periconceptional cold-like syndrome as well as to have had a history of previous spontaneous abortion. Inflammatory infection (aOR, 3.56; 95% CI, 2.07-6.13) and chemical exposure (aOR, 2.77; 95% CI, 1.78-4.32) was associated with a higher risk of microtia. However, threatened abortion was not the risk factor (aOR, 1.14; 95% CI, 0.78-1.67), using progesterone may increase the risk (aOR, 1.92; 95% CI, 1.03-3.59).
  
  
  CONCLUSIONS
  The results of phenotypic characterization analysis were similar to other studies. By controlling the effects of potential confounders, some risk factors could be teratogens of isolated and sporadic microtia in East China.
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital, Fudan University, Shanghai, China.
authors.forename: Chen-long
authors.initials: CL
authors.lastname: Li
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital, Fudan University, Shanghai, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital, Fudan University, Shanghai, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Shan
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, The First Affiliated Hospital, Zhengzhou University, Zhengzhou, China.
authors.forename: Shao-juan
authors.initials: SJ
authors.lastname: Hao
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Children's Hospital of Shanghai, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Jin
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Feng-hua
authors.initials: FH
authors.lastname: Qing
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital, Fudan University, Shanghai, China; Hearing Medicine Key Laboratory, National Ministry of Public Health, Shanghai, China. Electronic address: ty.zhang2006@aliyun.com.
authors.forename: Tian-yu
authors.initials: TY
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D065817:Congenital Microtia / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D012307:Risk Factors; D012737:Sex Factors
keywords: China; Clinical analysis; Epidemiology; Microtia; Risk factor