title: Low maternal middle cerebral artery Doppler resistance indices can predict future development of pre-eclampsia.
abstract: OBJECTIVE
  To determine if decreased resistance (vasodilatation) in the maternal middle cerebral artery (MCA) in the second trimester can predict third-trimester development of pre-eclampsia.
  
  
  METHODS
  Four-hundred and five low-risk gravidas had MCA transcranial Doppler (TCD) once in the second trimester. Maternal/neonatal outcomes were evaluated after delivery. Mean blood pressure, MCA velocities, resistance index (RI), pulsatility index (PI) and cerebral perfusion pressure (CPP) were compared between normotensive and pre-eclamptic cohorts.
  
  
  RESULTS
  Seven subjects (1.7%) developed pre-eclampsia. An RI of < 0.54 and a PI of < 0.81 were clinically useful in predicting subsequent pre-eclampsia. Areas under the receiver-operating characteristics curves for RI and PI were 0.93 and 0.93, respectively, with optimal sensitivity and specificity of 86% and 93% for both variables. Positive and negative likelihood ratios were 11.8/0.15 (RI) and 12.3/0.15 (PI).
  
  
  CONCLUSIONS
  TCD indices of low maternal MCA resistance in the second trimester are predictive of the subsequent development of pre-eclampsia in a low-risk, ethnically homogeneous population.
authors.affiliation: Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX 77030, USA. belfort@bcm.edu
authors.forename: M
authors.initials: M
authors.lastname: Belfort
authors.forename: T
authors.initials: T
authors.lastname: Van Veen
authors.forename: G L
authors.initials: GL
authors.lastname: White
authors.forename: S
authors.initials: S
authors.lastname: Kofford
authors.forename: J
authors.initials: J
authors.lastname: Allred
authors.forename: I
authors.initials: I
authors.lastname: Postma
authors.forename: M
authors.initials: M
authors.lastname: Varner
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001794:Blood Pressure; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011225:Pre-Eclampsia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal; D014655:Vascular Resistance; D014664:Vasodilation