Journal of Ultrasound in Medicine, Vol 14, Issue 5 343-348, Copyright © 1995 by American Institute of Ultrasound in Medicine
Performance of Doppler ultrasonography as a screening test in low risk pregnancies: results of a multicentric study
T. Todros, E. Ferrazzi, D. Arduini, S. Bastonero, V. Bezzeccheri, M. Biolcati, B. Bonazzi, S. Gabrielli, G. L. Pilu, G. Rizzo and al. et
Istituto di Ginecologica e Ostetrica, Universita di Torino, Italy.
To assess the efficacy of the Doppler velocimetry of the uterine and
umbilical arteries as a screening test for preeclampsia and fetal growth
retardation, we studied 916 low risk pregnancies. The S/D ratios of the
uterine and umbilical arteries were obtained at 19 to 24 weeks and at 26 to
31 weeks of gestational age. Mean values, receiver operator curves, and the
diagnostic accuracy of the tests were calculated for the following
end-points: (1) pregnancy-induced hypertension, (2) low birth weight for
gestational age, (3) small for gestational age with abnormal outcome, (4)
pregnancy-induced hypertension needing preterm delivery. The prevalences
for these outcomes were 3.4%, 4.6%, 1%, and 0.7%, respectively. The study
was blinded. The umbilical and uterine artery S/D ratios were significantly
higher in the abnormal than in the normal outcome group. When uterine
arteries were studied at 19 to 24 weeks, sensitivity was 59% in the
detection of pregnancy-induced hypertension, 11% in the detection of small
for gestational age fetuses, 33% in the detection of small for gestational
age fetuses with abnormal outcome, and 83% in the detection of pregnancy
induced hypertension needing preterm delivery; the corresponding values for
specificity were 69%, 94%, 94%, and 68%. At 26 to 31 weeks the sensitivity
values were respectively, 69%, 58%, 75%, and 100% and specificity values
were 80%, 59%, 39%, and 79%. When umbilical arteries were studied at 19 to
24 weeks, sensitivity was 38% in the detection of pregnancy-induced
hypertension, 46% in the detection of small for gestational age fetuses,
78% in the detection of small for gestational age fetuses with abnormal
outcome, and 67% in the detection of pregnancy-induced hypertension needing
preterm delivery. The corresponding values of specificity were 74% for all
four groups. At 26 to 31 weeks the sensitivity values were 38%, 43%, 87%,
and 67%, respectively, and specificity values were 80% for all four groups.
We concluded that Doppler examinations of the uterine and umbilical
arteries can detect, at midpregnancy, the severe forms of pregnancy-induced
hypertension and small for gestational age fetuses but they cannot be used
to screen a low risk population in which the prevalence of the disease is
low, and hence the positive predictive value is low.
