Zdravniški Vestnik (Nov 2001)

UTERINE ARTERY BLOOD FLOW MEASUREMENTS IN NORMAL AND ABNORMAL PREGNANCIES

  • Zvonko Šoštarič

Journal volume & issue
Vol. 70, no. 11

Abstract

Read online

Background. Ultrasound Doppler measurements can provide important and useful information about the uterine circulation in pregnant women with hypertension and fetal growth retardation. The aim of this prospective study was to assess the velocity of uterine artery blood flow and compare the current known pulsatility index (PI) and resistance index (RI) with the new parameter – the compliance index (CI). The purpose of the research was an early detection and prediction of fetal growth retardation and hypertension in pregnancy. The research was made on Gynecology and Obstetrics Department of General Hospital in Nova Gorica from June 1994 to October 1996. All pregnant women were informed of the purpose and joined the research voluntarily signing an informed consent. The research was approved by The Board for medical and ethical matters.Methods. A group of 80 randomly-selected pregnant women with single pregnancy was included in the research. The group was at the end of study divided into normal and pathological. The normal group was composed of 44 pregnant women with normal pregnancy, and the pathological group of 36 pregnant women with hypertension and fetal growth retardation. Doppler measurements of the uterine artery were made in a period between 18th and 40th week of pregnancy. The position of the placenta was also taken into account. A comparison of the velocity of blood flow, the PI and RI and the CI was made. The fetal body weight was also assessed on the basis of ultrasound measurements of fetal parameters.Results. Analysis of general data between the groups revealed a statistically significant difference in the appearance of proteinuria, emergency Cesarean delivery and 2.6 times bigger relative risk for fetal anomalies in the pathological group. Measurements of fetal parameters and evaluation of fetal body weight showed a 87.5% sensitivity and a 96.9% specificity in the detection of intrauterine growth restriction.There is a statistically important increase in the maximum systolic velocity and the velocity of blood flow in the notch, but without significant differences between normal and pathological group.Analysis of the PI throuhgout the pregnancy revealed a statistically significant fall except in the pathological group on contralateral side of the placenta, while between the groups there were no significant differences. Analysis of measurements of the RI throuhgout the pregnancy revealed a statistically significant fall in the normal group, while in the pathological group the fall was not statistically significant neither on the placental, neither on the other side of the placenta. There were also no differences in RI between the normal and the pathological group. Analysis of the values of the CI between 21st and 34th week of pregnancy revealed a statisticaly significant difference between the normal and the pathological group. The prognostic value of the CI for the detection of hypertension and intrauterine growth restriction in this period showed a 44% sensitivity, a 75% specificity and a 45% positive predictive value. In the group of pregnant women with proteinuric hypertension the prognostic value of the CI in the same period showed a 70.6% sensitivity and a 62.2% specificity.Conclusions. On the basis of obtained results it can be stated, that among all compared parameters, the CI of the uterine artery, measured on the side of the placenta, is the most sensitive parameter for the early prediction and detection of fetal growth retardation and hypertension, especially proteinuric. The results also confirmed the role of placentation on the changes in blood flow through the uterine artery. The low prognostic values for sensitivity, specificity and predictive value of a positive result can be explained by the large dispersion of measurements, the small number of subjects and not in the least also by our therapeutic procedures. The last two reasons probably contributed to the fact that no differences in the perinatal results between the two groups were found, and that there was no perinatal loss.

Keywords