title: Comparative study of transabdominal and transvaginal uterine artery Doppler pulsatility indices at 11-13 + 6 weeks.
abstract: OBJECTIVE
  The objective of this study was to compare two approaches to determine the uterine artery pulsatility index (PI) as a screening measure for preeclampsia.
  
  
  METHODS
  Comparative analysis of the PI values obtained from transabdominal and transvaginal Doppler ultrasound in 351 women with singleton pregnancies who were examined between May and June 2009 during routine morphological study and risk calculation of chromosome anomalies at 11-13 + 6 weeks of gestation.
  
  
  RESULTS
  The mean PI measured transabdominally was 1.83 [95% confidence interval (CI) 1.78-1.89], but when measured transvaginally it was 1.98 (95% CI 1.93-2.08) (p < 0.05). Transabdominal mean PI was observed to decrease as the crown-rump length (CRL) increased: 1.96 (95% CI 1.80-2.12) for CRL <60 mm and 1.71 (95% CI 1.56-1.87) for CRL ≥70 mm (p < 0.05). The transvaginally measured indices were 2.09 (95% CI 1.93-2.26) and 1.78 (95% CI 1.64-1.92), respectively, for the same CRL groups (p < 0.05). A weak correlation was found between the mean PI and the mean CRL using Spearman's rho correlation (-0.20 for abdominal measures and -0.21 for vaginal measures, p < 0.001).
  
  
  CONCLUSIONS
  Transabdominal and transvaginal Doppler ultrasound measurements of the uterine artery PI were significantly different. The latter approach yielded significantly higher values than the first.
authors.affiliation: Prenatal diagnosis and fetal therapy Unit, Obstetrics and Gynecology Department, Complejo Hospitalario Universitario Insular Materno-Infantil de Canarias, Las Palmas de Gran Canaria, Spain. walterplasencia@mac.com
authors.forename: Walter
authors.initials: W
authors.lastname: Plasencia
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Barber
authors.forename: Eva E
authors.initials: EE
authors.lastname: Alvarez
authors.forename: Javier
authors.initials: J
authors.lastname: Segura
authors.forename: Leonor
authors.initials: L
authors.lastname: Valle
authors.forename: Jose A
authors.initials: JA
authors.lastname: Garcia-Hernandez
mesh_terms: D000005:Abdomen; D000328:Adult; D005260:Female; D005865:Gestational Age; D006801:Humans; D011225:Pre-Eclampsia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011673:Pulsatile Flow; D012039:Regional Blood Flow; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal; D014599:Uterus / Q000098:blood supply*; D014621:Vagina