British Journal of Obstetrics and Gynaecology zyxwvut October zyxwvutsr 1YY1, zyxwvuts Vol. 98, pp. zyxwvut 956-963 Doppler flow velocity waveform analysis in high risk pregnancies: a randomized controlled trial JOHN P. NEWNHAM, MICHELLE R-A. O’DEA, KAREN P. REID, DEAN A. DIEPEVEEN Abstract Objective-To test whethcr the introduction of Doppler wavcform analysis into the ultrasound department of a tertiary level hospital reduces neonatal morbidity and improves obstetric management. Design-A randomized controlled trial. Setting-Department of Ultrasound, King Edward Memorial Hospital, Perth, Westcrn Australia. Subjecrs-505 women with pregnancy abnormalities referred to an ultrasound department for fetal investigation during the third trimester. Zntervention-Continuous wave Doppler studies of umbilical and utero- placcntal arterial circulations. Results were rcvealed to patients and clinicians. Main outcome measures-Principal end point was the duration of neonatal stay in hospital; other end points included the number and type of fetal heart rate monitoring studies, obstetric intervcntions, frequency of fetal distress, birthweight, Apgar scores and need for neonatal intensive care. Results-Thcre was no effect on the duration of neonatal stay in hospital. Small trends in obstetric management were observed with study group patients having fewcr contraction stress tests, less likelihood of antepartum fetal distress, and more likelihood of fetal distrcss after induction of labour leading to emergency cacsarean section. Depressed Apgar scores were more frequent in the study group. Conclusion-Introduction of Doppler waveform studies did not result in rcduced neonatal morbidity but did have a small effect on obstetric management. For each institution the role of Doppler studies in late pregnancy will be influenced by the usage of other tests of fetal welfare already entrenched in clinical practice. In recent years examination of umbilical and uteroplacental arterial waveforms by Doppler University Department of Obstetrics and Gynaecology, King Edward Memorial Hospital for Women, Perth, Western Australia J. P. NEWNHAM Associate Professor M. R-A. O’DEA Research Midwife K. P. REID Research Midwife zyxwvuts D. A. DIEPEVEEN Research Oficer Corrcspondcnce: John P. Ncwnham MD, King Edward Mcmorial Hospital for Women, 374 Bagot Road, Subiaco, Perth, Westcrn Australia 6008. 956 ultrasound has presented a new and exciting method of investigation in the management of pregnancy. Continuous wave Doppler systems provide an indirect estimate of placental vas- cular resistance (Giles etal. 1985). They are rela- tively inexpensive and technically easy to use. It is tempting to speculate that introduction of this technology into clinical practicc will improve clinical management and reduce perinatal mor- bidity. However, the availability of new tech- nology does not neccssanly justify its use. Justification for widespread acceptance of any new tcst requires demonstration of its efficacy in