title: Location of the placenta or the umbilical cord insertion site in the lowest uterine segment is associated with low maternal blood pressure.
abstract: OBJECTIVE
  To evaluate whether placental abnormalities and umbilical cord insertion site affect the occurrence of pre-eclampsia and maternal blood pressure.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Showa University Hospital, Tokyo, Japan.
  
  
  METHODS
  A total of 5722 consecutive women who delivered singleton infants were included in the study.
  
  
  METHODS
  The associations of placental abnormalities, the location of the placenta, the location of the cord insertion site, and maternal background with the occurrence of pre-eclampsia and maternal blood pressure at the term of pregnancy were analysed.
  
  
  METHODS
  Pre-eclampsia and maternal blood pressure at the term of pregnancy.
  
  
  RESULTS
  Pre-eclampsia was observed in 236 women (4.1%). Pre-eclampsia was frequently observed in women with placental form abnormalities (odds ratio 3.0) and infarction of the placenta (odds ratio 5.3). Pre-eclampsia was observed in 0 and 4.1% of women with and without placenta praevia, respectively (P = 0.004), and in 0 and 2.5% of women with and without low cord insertion during the first trimester, respectively (P = 0.018). After adjustment for confounding variables, the multivariate regression analyses revealed reductions of 8.4 and 5.0 mmHg in systolic and diastolic blood pressure, respectively, in women with placenta praevia compared with women without placenta praevia, and reductions of 4.3 and 3.1 mmHg in systolic and diastolic blood pressure, respectively, in women with low cord insertion during the first trimester compared with women without low cord insertion.
  
  
  CONCLUSIONS
  Not only placenta praevia but also low cord insertion are associated with low frequencies of pre-eclampsia and low maternal blood pressure.
authors.affiliation: Department of Obstetrics and Gynaecology, Showa University School of Medicine, Tokyo, Japan. hasejun@oak.dti.ne.jp
authors.forename: J
authors.initials: J
authors.lastname: Hasegawa
authors.forename: A
authors.initials: A
authors.lastname: Sekizawa
authors.forename: A
authors.initials: A
authors.lastname: Farina
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: R
authors.initials: R
authors.lastname: Matsuoka
authors.forename: K
authors.initials: K
authors.lastname: Ichizuka
authors.forename: T
authors.initials: T
authors.lastname: Okai
mesh_terms: D000328:Adult; D001794:Blood Pressure; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015999:Multivariate Analysis; D010920:Placenta / Q000002:abnormalities*; D010923:Placenta Previa / Q000503:physiopathology*; D011225:Pre-Eclampsia / Q000209:etiology*; D011247:Pregnancy; D012044:Regression Analysis; D012189:Retrospective Studies; D014470:Umbilical Cord / Q000002:abnormalities*