title: The volume of the chorion villosum is associated with the location of the umbilical cord in the first trimester.
abstract: OBJECTIVE
  To clarify whether villous placental volumes in cases with low cord insertion (CI) are smaller than those with normal cord insertion.
  
  
  METHODS
  A prospective cohort study was conducted to evaluate the association between location of umbilical CI and placental volume at 11 to 13 weeks' gestation. An ultrasound examination was performed to measure the crown-rump length, the distance between the histological internal cervical os and the CI site, the placental volume, and the uterine arterial blood flow. To standardize the distribution of the ultrasonographic measurements, we transformed data by crown-rump length-weighted linear regression.
  
  
  RESULTS
  Six hundred fifty-nine subjects were analyzed. Scatter plots showed a slightly positive correlation between the z-scores of the distance from the CI site to the internal cervical os and villous placental volume (r = 0.102, p = 0.009) and a negative correlation between the z-scores of the villous placental volume and the uterine arterial pulsatility index (r = -0.165, p < 0.001) as well as the uterine arterial resistance index (r = -0.187, p < 0.001).
  
  
  CONCLUSIONS
  The placental volume was likely to be smaller in cases with CI located in the lower uterine segment.
authors.affiliation: Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan. tsumisama1975@mail.goo.ne.jp
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Nakamura
authors.forename: Junichi
authors.initials: J
authors.lastname: Hasegawa
authors.forename: Shoko
authors.initials: S
authors.lastname: Hamada
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: D002823:Chorion / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D018568:Crown-Rump Length; D005260:Female; D006801:Humans; D009929:Organ Size; D010920:Placenta / Q000000981:diagnostic imaging; D021041:Placental Circulation; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011673:Pulsatile Flow; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000502:physiology; D014470:Umbilical Cord / Q000000981:diagnostic imaging*