title: Abnormal Middle Cerebral Artery Doppler Associates with Spontaneous Preterm Birth in Normally Grown Fetuses.
abstract: OBJECTIVE
  Our aim was to evaluate whether Doppler changes in the fetal middle cerebral (MCA) and umbilical arteries (UA) suggesting fetal hypoxemia precede the onset of spontaneous preterm birth (PTB).
  
  
  METHODS
  We studied 2,340 appropriate-for-gestational-age singleton pregnancies that had MCA and UA pulsatility indices (PI) recorded at 28-32 weeks. Values including the cerebroplacental ratio (CPR) were converted into multiples of the median and evaluated according to both gestational age at the onset of labor and the interval between ultrasound and labor. ROC analysis was used to calculate the ability in the prediction of spontaneous PTB before 32, 34 and 37 weeks' gestation.
  
  
  RESULTS
  While no correlations were observed for the UA PI and CPR, lower MCA PI values were associated with an earlier onset of labor (p < 0.001) and a shorter ultrasound-labor interval (p = 0.028). The ROC analysis at different gestational ages and intervals to labor indicated that MCA PI values were poorly predictive of spontaneous PTB (all areas under the curve <0.7).
  
  
  CONCLUSIONS
  Low MCA PI values at 28-32 weeks are associated with subsequent spontaneous PTB, indicating that fetal hypoxemia unrelated with placental disease might be implicated in the onset of labor. This association, however, is unlikely to be useful in the prediction of PTB.
authors.affiliation: Servicio de Obstetricia, Hospital Universitario y Politx00E9;cnico La Fe, Valencia, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Morales-Roselló
authors.forename: Asma
authors.initials: A
authors.lastname: Khalil
authors.forename: Sylvia
authors.initials: S
authors.lastname: Salvi
authors.forename: Rosemary
authors.initials: R
authors.lastname: Townsend
authors.forename: Yaami
authors.initials: Y
authors.lastname: Premakumar
authors.forename: Alfredo
authors.initials: A
authors.lastname: Perales-Marín
mesh_terms: D005260:Female; D005333:Fetus / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D007752:Obstetric Labor, Premature; D011247:Pregnancy; D047928:Premature Birth / Q000503:physiopathology*; D012372:ROC Curve; D012189:Retrospective Studies; D014469:Umbilical Arteries / Q000000981:diagnostic imaging