title: Frequency of malformed infants in a tertiary center in Hokkaido, Japan over a period of 10 years.
abstract: OBJECTIVE
  This retrospective study was performed to determine the frequency of malformed infants born at a tertiary center in Hokkaido, Japan. The accuracy of prenatal diagnosis rates was also investigated.
  
  
  METHODS
  An observational study was performed using data of 1509 and 1743 newborn infants at a single center during two study periods, 2005-2009 (first) and 2010-2014 (second), respectively. Cases including minor anomalies (accessory auricle, nevus and fistula auris congenita) were not included.
  
  
  RESULTS
  In total, 274 and 569 malformations were identified in 191 and 337 newborn infants in the first and second study periods, respectively. The number of malformed infants increased significantly over time (13% [191/1509] vs 19% [337/1743], respectively; P < 0.001), mainly as a result of an increase in cases of congenital heart disease (CHD), from 59 to 141 (31% [59/191] vs 42% [141/337] of all malformed infants in the first and second periods, respectively). The overall accurate prenatal diagnosis rate improved over time from 47% (128/274) to 58% (329/569) because of significant improvements in accurate prenatal diagnosis of CHD subtypes (23% [16/70] vs 65% [151/232] in the first and second periods, respectively, P < 0.0001).
  
  
  CONCLUSIONS
  The frequency of malformed newborns was higher in the tertiary center than in the general population. The increased number of cases with prenatal suspicion and diagnosis of CHD contributed to the increased frequency of malformed infants during the study period.
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Itaru
authors.initials: I
authors.lastname: Hayasaka
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Cho
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Uzuki
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Morioka
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Akimoto
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ishikawa
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Kohta
authors.initials: K
authors.lastname: Takei
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Morikawa
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ariga
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Minakami
mesh_terms: D000013:Congenital Abnormalities / Q000453:epidemiology*; D005260:Female; D006330:Heart Defects, Congenital / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D062606:Tertiary Care Centers / Q000706:statistics & numerical data*
keywords: congenital heart disease; congenital malformation; fetal echocardiography; prenatal diagnosis; tertiary center