Systolic or diastolic notch in uterine artery blood flow velocity waveforms in hypertensive pregnant patients: relationship to outcome
Thaler, I.; Weiner, Z.; Itskovitz, J.
Obstetrics and Gynecology 80(2): 277-282
1992
ISSN/ISBN: 0029-7844 PMID: 1635744 Document Number: 403779
To identify the relationship between a systolic or diastolic notch in uterine artery flow velocity waveforms and pregnancy outcome, we studied 140 hypertensive pregnant women with transvaginal, image-directed ulsed Doppler ultrasound. The subjects were classified according to the presence or absence of a systolic or diastolic notch. In 14 with a systolic and 25 with a diastolic notch, the resistance indexes in the uterine arteries on both sides of the uterus were significantly higher than in 101 subjects without a notch. Those with notches had significantly higher rates of fetal growth retardation and cesarean delivery because of fetal distress. Significantly more infants born to women with a notch spent longer than 48 hours in the neonatal intensive care unit. Subjects with a systolic notch also had significantly higher rates of abnormal fetal heart rate patterns during labora and low Apgar scores at 5 minutes. Fifty-one women with elevated resistnce indexes in both uterine arteries were divided into two groups according to the resistance index in the umbilical artery. Each group was subdivided according to the presence or absence of a systolic or diastolic notch in the uterine artery flow velocity waveforms. In the group with a normal resistance index in the umbilical artery, five women had growth-retarded fetuses when a notch was present (N = 8), compared with none in women without a notch (N = 11) (P < 0.005). The respective figures for the group with abnormal umbilical artery resistance indexes were 14 of 19 (73.7%) and two of 13 (15.4%) (P < .002). Among subjcts without a notch in the uterine arteries and a normal resistance index in the umbilical artery, there were not statistically significant differences in outcomes between those with a normal resistance index (N = 30) and those with an abnormally elevated resistance index (N = 11) in the uterine artery. We conclude that the presence of a notch in uterine artery flow velocity waveforms is a better predictor of poor pregnancy outcome than is the resistance index alone. The presence of a systolic notch signals that the uteroplacental circulation is greatly impaired, and carries the worst prognosis for the fetus.