title: Causes of intrauterine fetal death are changing in recent years.
abstract: OBJECTIVE
  To investigate, how causes of intrauterine fetal death (IUFD) have changed in recent years with the advancement of prenatal diagnosis at a single perinatal center in Japan.
  
  
  METHODS
  Medical records were retrospectively reviewed for all cases of IUFDs that occurred between 2001 and 2014. The most commonly associated causes of fetal deaths were compared between 2001-2007 and 2008-2014.
  
  
  RESULTS
  The number of IUFD after 20 weeks' gestation/all deliveries in our center was 38/6878 cases (0.53%) in 2001-2007 and 35/7326 (0.48%) in 2008-2014. The leading cause of IUFD in 2001-2007 was fetal abnormalities (43.2%), the prevalence of which was only 8.6% in 2008-2014 (P<0.01). Meanwhile, the prevalence of umbilical cord abnormalities was relatively increased from 30.0% in 2001-2007 to 54.5% in 2008-2014 (P=0.06). In 2001-2007, chromosomal abnormalities were frequently observed (56% of IUFDs due to fetal abnormalities). Hyper-coiled cord (HCC) and umbilical ring constrictions were the most frequent cause of IUFD in both periods. The relatively decreased prevalence of IUFD due to velamentous cord insertion and umbilical cord entanglement, HCC and umbilical cord constriction was increased.
  
  
  CONCLUSIONS
  The prevalence of IUFD due to fetal abnormalities was reduced, but IUFD associated with umbilical cord abnormalities tended to increase relatively.
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Takita
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan.|Department of Obstetrics and Gynecology, St. Marianna University School of Medicine, Kanagawa, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Hasegawa
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Arakaki
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Oba
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Ryu
authors.initials: R
authors.lastname: Matsuoka
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sekizawa
mesh_terms: D000328:Adult; D005260:Female; D005313:Fetal Death / Q000209:etiology*; D006801:Humans; D007564:Japan; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000639:trends; D012189:Retrospective Studies
keywords: Chromosome abnormality; fetal anomaly; hypercoiled cord; intrauterine fetal death (IUFD); umbilical cord; velamentous cord insertion