Evaluation of Pathophysiolosical Aspects of IUGRs by Nonstress Test and Pulsed-Doppler Method
津崎 恒明1, 三浦 裕和1, 戸田 稔子2, 木内 誠2
Tsuneaki TSUZAKI1, Hirokazu MIURA1, Toshiko TODA2, Makoto KIUCHI2
1Department of Obstetrics and Gynecology, Yohka Municipal Hospital, 2Department of Obstetrics and Gynecology, Tottori University School of Medicine
IUGR, Nonstress test, Pulsed-Doppler methed, Pathophysiology, Resistance index
The correlation between nonstress test (NST) and pulsed-Doppler flowmetric findings was studied in 23 cases of intrauterine growth retardations (IUGRs) and 23 cases of appropriate for dates (AFDs) in which gestational age at birth was between 33 and 41 weeks. NST findings were classified into three groups,: reactive, non-reactive and abnormal. A pulsed-Doppler flowmetric study was performed on umbilical arteries (UA) and middle cerebral arteries (MCA) with evaluation parameter of resistance index (RI). The mean RI in UA of IUGRs correlated well not only with NST findings but also with mean birthweight. On the other hand, the parameter that correlated with NST findings was the RI of MCA in AFDs. The mean MCA/UA ratio which means RI ratio of MCA to UA was lower than 1.0 in the non-reactive and abnormal groups of IUGRs. In IUGRs, the mean variability in the group in which MCA/UA was more than 1.0 was significantly larger than in the group in which the MCA/UA was less than 1.0. The relation between RI of UA and mean variability can thus be used as the basis for a negative prognosis for IUGRs in which mean variability is less than 5 bpm and RI of UA is higher than 0.7. We propose three clinical alarm signs for IUGRs.: 1) RI of UA is higher than 0.7. 2) MCA/UA ratio is lower than 1.0. 3) Mean variability in NST is less than 5 bpm.