LONGITUDINAL DOPPLER ULTRASONOGRAPHIC ASSESSMENT OF ALTERATIONS IN REGIONAL VASCULAR-RESISTANCE OF ARTERIES IN NORMAL AND GROWTH-RETARDED FETUSES

The objective of this longitudinal study was to evaluate alterations i n regional vascular resistance of arteries with advancing gestation in normal and growth-retarded fetuses. Color Doppler flow imaging and pu lsed Doppler ultrasonographic assessments were performed on 13 normal and 7 growth-retarded fetuses, ranging from 15 to 40 weeks menstrual a ge. The pulsatility index was calculated for middle cerebral artery, d escending aorta, splenic artery, renal artery, femoral artery and umbi lical artery, respectively. Optimal models for these pulsatility index values were determined by regression analysis. A normal range of the pulsatility index for each artery generated in the normal fetuses. In the middle cerebral artery, the models showed a parabolic pattern duri ng pregnancy in the two groups and the predicted pulsatility index val ues in growth-retarded fetuses were always lower than those in the nor mal fetuses, especially late in pregnancy. In the renal artery, the pr edicted pulsatility index values in growth-retarded fetuses were highe r than those in normal fetuses near term. In other arteries, the predi cted pulsatility index values showed their own specific patterns and t here were no significant differences in predicted pulsatility index va lues in the two groups. In conclusion, alterations in regional vascula r resistance of arteries with advancing menstrual age occur evidenced in both normal and growth-retarded fetuses.