title: Cerebral, umbilical, and uterine resistance using Doppler velocimetry in postterm pregnancy.
abstract: The purpose of this study is to assess alterations in vascular resistance as measured by Doppler ultrasound in the postterm fetus. Forty-five postterm patients (greater than or equal to 287 days gestation by "good" dates) underwent Doppler velocimetry and calculation of systolic to diastolic (S/D) ratios of the umbilical, internal carotid, and uterine artery waveforms within 7 days of delivery. Patients were divided into two groups. Group 1 consisted of 26 patients with normal antepartum fetal surveillance that included reactive nonstress test and an amniotic fluid index (using the four-quadrant technique) equal to or greater than 5 cm. Group 2 consisted of 19 patients with antepartum compromise on the antepartum fetal surveillance tests. There was significantly greater (p less than .05) morbidity in group 2 compared to group 1 as judged by cesarean section for fetal distress (47% vs 15%), meconium at delivery (53% vs 4%), and 5-minute Apgar score less than 7 (30% vs 4%). There were no significant differences in the umbilical and uterine artery S/D ratios in the two groups, although patients in group 2 had significantly lower cerebral S/D ratios (3.6 +/- .5) compared to group 1 (4.4 +/- 0.4) (p less than .05). The ratio of cerebral to placental (umbilical) resistance in group 2 was significantly lower (1.1 +/- .3) compared to group 1 (1.8 +/- .3) (p less than .05). There was a low incidence of abnormal umbilical (greater than 3) and uterine (greater than 2.6) S/D ratios in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles.
authors.forename: H S
authors.initials: HS
authors.lastname: Brar
authors.forename: J
authors.initials: J
authors.lastname: Horenstein
authors.forename: A L
authors.initials: AL
authors.lastname: Medearis
authors.forename: L D
authors.initials: LD
authors.lastname: Platt
authors.forename: J P
authors.initials: JP
authors.lastname: Phelan
authors.forename: R H
authors.initials: RH
authors.lastname: Paul
mesh_terms: D001783:Blood Flow Velocity; D002343:Carotid Artery, Internal / Q000502:physiology; D005260:Female; D005323:Fetal Monitoring; D005333:Fetus / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology*; D011256:Pregnancy Outcome; D011273:Pregnancy, Prolonged / Q000502:physiology*; D014463:Ultrasonography; D014469:Umbilical Arteries / Q000502:physiology; D014599:Uterus / Q000098:blood supply; D014655:Vascular Resistance