Doppler ultrasound screening predicts recurrence of poor pregnancy outcome in subsequent pregnancies, but not the recurrence of PIH or preeclampsia

Objective: To assess the role of Doppler uterine artery screening in the prediction of recurring hypertensive disorders in a high-risk population. Methods: Ninety-four women with a history of hypertensive disorders in previous pregnancies underwent ultrasound color Doppler to analyze blood flow in the uterine arteries at 21-22 weeks of gestation. We evaluated the performance of the Pulsatility Index (PI) as well as the diastolic notch to predict recurring hypertensive disorders. Outcome measures were the recurrence of hypertensive disorders, and poor pregnancy outcome due to intrauterine death growth retardation, intrauterine death, placental abruption, hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome, eclampsia, or premature birth. Onset of symptoms was before 35 weeks in all cases of poor pregnancy outcome. Results: Doppler flow recordings were obtained from a well-defined location in both uterine arteries. The predictive value of the uterine artery PI for recurring hypertensive disease was poor and not significant; interestingly, however, the predictive values for poor pregnancy outcome were good (sensitivity 83%, specificity 71%, p <0.001). The PI also provides a good test for intrauterine growth retardation (sensitivity 80%, specificity 69%, p <0.01). The "diastolic notch" did not perform as well as the PI. Conclusions: Uterine artery screening did significantly predict the recurrence of poor pregnancy outcome due to hypertensive complications in this high-risk group. In contrast, gestational hypertension and preeclampsia with normal pregnancy outcome were not significantly predicted by uterine artery screening

Uterine artery Doppler flow and uteroplacental vascular pathology in normal pregnancies and pregnancies complicated by pre-eclampsia and small for gestational age fetuses

This study was conducted to investigate the association between uterine artery Doppler flow patterns and uteroplacental vascular pathology in normal and complicated pregnancies in view of the recently described concept of heterogeneous causes of hypertensive pregnancy complications. Forty-three women whose pregnancies were complicated by pre-eclampsia, the HELLP (Haemolysis, Elevated Liver enzymes, Low Platelets) syndrome and/or small for gestational age (SGA) fetuses and 27 women with normal pregnancies undergoing elective caesarean section were included. We obtained uterine artery Doppler waveforms at a mean of 4 days before delivery. Placental bed biopsies were obtained at caesarean section and analysed for physiological changes and pathological changes. We found that abnormal uterine artery Doppler flow was strongly associated with pregnancy complications. Absence of physiological changes was seen in 58 per cent of complicated pregnancies and 40 per cent of normal pregnancies. Pathological changes were seen in 58 per cent of complicated pregnancies and 53 per cent of normal pregnancies; they occurred in spiral arteries with and without physiological changes, and there was no significant correlation to Doppler results. In conclusion, absence of physiological changes is associated with abnormal uterine artery Doppler flow and pregnancy complications. However, there is a gradient in the severity of uteroplacental vascular pathology and the correlation with pregnancy complications is not as strong as previously thought. There is also a significant degree of uteroplacental vascular pathology in normal pregnancies with normal uterine artery Doppler flow. This variation may be partly due to sampling error, as a typical biopsy contains only one or two spiral arteries. We hypothesize that additional factors might be necessary to induce the clinical syndrome of pre-eclampsia. (C) 2001 Harcourt Publishers Ltd

Second trimester Doppler ultrasound screening of the uterine arteries differentiates between subsequent normal and poor outcomes of hypertensive pregnancy: two different pathophysiological entities?

The 'classical' concept that pregnancy-induced hypertension (PIH) and pre-eclampsia (PE) primarily originate from defective placentation in early pregnancy has been challenged recently. There is growing evidence that other factors, including maternal predisposing conditions, also play a significant role in the pathophysiology of PIH and PE. The aim of the present study was to test the hypothesis that PIH and PE with an early onset and poor pregnancy outcome is associated with defective placentation, e.g. inadequate spiral artery dilatation and subsequent reduced uteroplacental perfusion, whereas PIH and PE with normal pregnancy outcome is not. Using Doppler ultrasound, we measured the uterine artery pulsatility index (PI) in a population of 531 nulliparous women in the 22nd week of gestation. Uterine artery PI was used as an index of resistance to blood flow in the uteroplacental circulation. Outcome measures were PIH/PE with or without poor pregnancy outcome, preterm birth and intra-uterine growth restriction (IUGR). The results revealed a striking difference between PI values for PIH/PE with and without poor pregnancy outcome. Uterine artery PI in the 22nd week was increased significantly in pregnancies which developed early-onset (before 35 weeks) PIH/PE with a poor pregnancy outcome. in contrast, uterine artery PI values were normal in women who developed PIH/PE, but had a good pregnancy outcome. There was a significant correlation between 22nd week uterine artery PI and subsequent preterm birth or IUGR. Our results indicate that only PIH/PE with poor pregnancy outcome is associated with defective placentation, whereas PIH/PE with good outcome is not. These findings support the concept of heterogeneous causes of hypertensive disorders of pregnancy

Quantification of the diastolic notch in Doppler ultrasound screening of uterine arteries

Objective To investigate a new method of quantification of the diastolic notch of the flow velocity waveforms of uterine arteries in the prediction of hypertensive disorders of pregnancy. Methods Pulsed-wave Doppler was used to obtain flow velocity waveforms (FVWs) from the uterine arteries at 21-22 weeks of gestation from 531 nulliparous women and 94 multiparous women at high risk. From the FVWs, both the pulsatility index (PI) and the notch index (NI) were calculated and the predictive values for both indices were compared using logistic regression analysis for mild and severe early onset hypertensive pregnancy complications. Results Both the PI and the NI were poor predictors for mild gestational hypertension and pre-eclampsia; predictive values for severe early onset disease, however, were much better Logistic regression analysis showed the NI has no additional value compared with the Pf in the prediction of either mild or severe disease. Conclusions The NI offers the possibility to quantify the diastolic notch in uterine artery analysis. Compared to the PI, this does not lead to better predictive values for hypertensive disorders of pregnancy