ABSTRACT
Background: There have been
researches on the evaluation of Doppler vascular impedance in hypertensive
disorders complicating pregnancy (HDCP). With respect to the method of analysis
used and the conclusions drawn in previous studies, different vessels were
usually viewed separately and independently. This study was designed to
evaluate Doppler vascular impedance changes in HDCP from a new perspective,
with original thought and insight into an ordinary issue. Methods: 273 pregnant
women (110 hypertensive pregnancies and 163 normotensive pregnancies) were
randomly included in a grouping case-control study conducted from February 10,
2011 to April 30, 2013. All women in the study underwent Doppler measurements
of six different vessels including the umbilical artery, the uterine arteries,
the placental bed spiral artery, the fetal middle cerebral artery and the fetal
renal artery. Doppler vascular impedance was presented as pulsatility index
(PI), resistance index (RI), and systolic and diastolic ratio (S/D). Doppler
changes in the hypertensive and normotensive groups were assessed by the
multilevel modeling approach with univariate and multivariate-adjusted
analyses. Results: According to multilevel modeling approach with
multivariate-adjusted analysis, a relatively average evaluation on Doppler
vascular impedance was provided. Hypertension was significantly associated with
positive effects on PI, RI and S/D values (coefficients were 0.10, 0.03 and
0.08, respectively; 95% CIs were 0.06 - 0.14, 0.02 - 0.04 and 0.04 - 0.11, respectively;
P values were all less than 0.001) in comparison with normotensive group.
Conclusion: According to an overall evaluation, Doppler vascular impedance in
hypertensive disorders complicating pregnancy was higher than in normotensive
pregnancy. The novel thought and approach applied in this research may bring
about inspirations for better understanding and assessment of the disease.