Journal of Ultrasound in Medicine, Vol 8, Issue 4 187-191, Copyright © 1989 by American Institute of Ultrasound in Medicine
Cerebral, umbilical, and uterine resistance using Doppler velocimetry in postterm pregnancy
H. S. Brar, J. Horenstein, A. L. Medearis, L. D. Platt, J. P. Phelan and R. H. Paul
Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles.
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)
