Journal of Ultrasound in Medicine, Vol 8, Issue 4 211-214, Copyright © 1989 by American Institute of Ultrasound in Medicine
Placental vascular resistance using umbilical velocimetry in patients undergoing cesarean section for fetal distress
H. S. Brar and L. D. Platt
Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles.
Peak systolic (S) to lowest end-diastolic (D) ratios (S/D) of umbilical
velocimetry have been used to assess downstream placental vascular
resistance and predict adverse pregnancy outcome. The purpose of this study
is to assess S/D ratios in patients undergoing cesarean section for
clinical fetal distress. Fifty-six patients were identified who had
umbilical velocimetry performed during antepartum fetal surveillance
(nonstress testing and amniotic fluid index) within 7 days of undergoing
cesarean section for fetal distress at Women's Hospital (Los Angeles, CA).
The mean gestational age at delivery was 36.5 +/- 2.5 weeks. Thirty (53.6%)
patients had elevated S/D ratios (greater than 3), 24 (42.9%) had abnormal
amniotic fluid indices, and 20 (35.7%) had abnormal nonstress testing.
Group 1 (N = 30) patients delivered small-for-gestational-age (SGA) fetuses
and group 2 (N = 26) patients delivered appropriately grown (AGA) fetuses.
In group 1, 24 (80%) patients had abnormal S/D ratios and 16 (53.3%) had
abnormal amniotic fluid indices, compared to only 6 (23.1%) with abnormal
S/D ratios and 8 (30.8%) with abnormal amniotic fluid indices in group 2 (p
less than .05). In contrast, 14 (53.8%) of the 26 patients in group 2 had
abnormal nonstress testing compared to only 6 (20%) of the 30 patients in
group 1 (p less than .05). Eighteen (69.2%) of the 26 patients in group 2
were post-term pregnancies; 20 (66.7%) of the 30 patients in group 1 had
chronic hypertension, pregnancy-induced hypertension, or superimposed
preeclampsia.(ABSTRACT TRUNCATED AT 250 WORDS)
