In general, about 5-10 % of women get this condition during their first pregnancy, while about 7% of women who have previously had children develop pre- eclampsia with subsequent pregnancies (WHO 1988).ĭoppler measurements can be obtained from the umbilical artery (UA), middle cerebral artery (MCA), ductus venosus (DV) and uterine arteries. Pre-eclampsia occurs more commonly during first pregnancies, with twins or triplets, in very young or older women, and when a woman has had pre-eclampsia in previous pregnancies.

Maternal hypertensive disorders are often associated with inadequate blood supply through the placenta. The relationship between abnormal uterine artery Doppler velocimetry and pre-eclampsia, intra-uterine growth retardation and adverse pregnancy outcome is well established (Aquilina 1996). The presence of reversed flow in the ductus venosus is an ominous sign. Ductus venosus leads directly into the vena cava allows some blood rich in oxygen and nutrients to be pumped out of the body without passing through the capillary beds in the kidney. The Doppler studies in Obstetrics and gynecology made a significant advance following describing waveforms in the ductus venosus, which is now recognized as a keyĮxamination to predict right heart failure in the hypoxic fetus and an important indicator of imminent fetal demise (Kiserud 1991). Centralization indicates a high resistance in the feto-placental circulation and the study of the middle cerebral artery shows inadequate cerebral perfusion. With the use of colour Doppler, in 1987, it was possible to study the middle cerebral artery in fetuses and compare to umbilical artery pulsatility index (PI) ratio to demonstrate centralization of the fetal circulation (Wladimiroff 1987).

Color flow imaging facilitates the detection of small vessels and slow blood-flow velocity. The structures that do not move are presented in basic gray-scale image. Customarily, flow towards the Doppler transducer is displayed in red and flow away from it is shown in blue. With this method, color is assigned to flow direction. In the colour Doppler imaging, a real-time, two-dimensional flow imaging technique utilizes an auto-correlation processor for the detection of a moving target. Subsequently these studies were done with colour Doppler and in many centers this has become an important screening technique to predict women at risk of pre-eclampsia. With the same systems, in 1983, Campbell published the assessment of the utero-placental circulation and that high resistance waveforms were obtained in pre-eclampsia (Campbell 1983) (Berkowitz 1988). The first Doppler ultrasound report using continuous wave assessment of umbilical artery flow was published in 1977 (Fitzgerald 1977). With the availability of this technique, it has been possible to study the circulation patterns and their pathologies non-invasively. Until this development the only way to study circulation was the invasive technique of angiography.

State University of Campinas (UNICAMP), Brazilĭoppler ultrasound has been used in almost every medical discipline to study blood flow in diseases where an alteration of this dynamic system is anticipated. (Protocol for a Cochrane Systematic Review)ĭepartment of Obstetrics and Gynaecology of the Center for Integral Attention to Women’s Health (CAISM) Postgraduate Training Course in Reproductive Health 2004ĭoppler ultrasound in high risk pregnancies

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