title: Umbilical cord insertion site in early gestation and development of placenta.
abstract: OBJECTIVE
  To study the relation of umbilical cord insertion (CI) site in early gestation and placental development from the chorion villosum.
  
  
  METHODS
  We ultrasonically measured the distance between the internal cervical Os and the CI site (CID), the distance between the internal cervical Os and lower placenta edge (PLD), and placental thickness at early (10-12 weeks) and mid-gestation (18-20 weeks).
  
  
  RESULTS
  CID in early gestation (CID-Early) correlated with CID in mid-gestation (r(2)=0.171; P<0.01). CID-Early correlated with PLD in mid-gestation (r(2)=0.093; P<0.01). Thickness of chorion villosum or placenta in early gestation did not correlate with that at mid-gestation. Increasing thickness of placenta was significantly higher in long CID-Early (> or =20 mm) cases than short cases (<20 mm) (P<0.05).
  
  
  CONCLUSIONS
  The process of placental development and the placental location are affected by CI location at early gestation, and suggests that this process might be affected by poor blood supply from the low uterine segment when CI site is close to the internal cervical Os.
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan. hasejun@oak.dti.ne.jp
authors.forename: Junichi
authors.initials: J
authors.lastname: Hasegawa
authors.forename: Ryu
authors.initials: R
authors.lastname: Matsuoka
authors.forename: Kiyotake
authors.initials: K
authors.lastname: Ichizuka
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sekizawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Okai
mesh_terms: D002584:Cervix Uteri / Q000000981:diagnostic imaging; D002824:Chorionic Villi / Q000000981:diagnostic imaging / Q000196:embryology; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D008954:Models, Biological; D010920:Placenta / Q000000981:diagnostic imaging / Q000196:embryology*; D010929:Placentation; D011247:Pregnancy; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal; D014470:Umbilical Cord / Q000000981:diagnostic imaging / Q000196:embryology*