UMBILICAL ARTERY DOPPLER VELOCIMETRY IN UNSELECTED AND LOW-RISK PREGNANCIES - A REVIEW OF RANDOMIZED CONTROLLED TRIALS

Objective Meta-analysis of data from controlled trials performed in po pulations at high risk have shown that umbilical artery Doppler veloci metry (umbilical Doppler) can reduce perinatal mortality. The individu al published trials among unselected or low risk populations have foun d no beneficial effect. Our objective was to evaluate the effect of ro utine use of the umbilical Doppler in unselected or low risk pregnanci es by reviewing all published and unpublished randomised controlled tr ials. Study design Systematically reviewing published and unpublished trials, we selected trials for the overview only if they were complete d randomised trials of umbilical Doppler in unselected or low risk pre gnancies. Of the seven trials examined, three were not included in the meta-analysis because of methodological problems or because they did not meet the inclusion criteria. We therefore included four trials: tw o in unselected and two in low risk populations. These four groups wer e comparable in their degree of maternal and perinatal risk. Using the Mantel-Haenzel statistical method and pooling the data, we considered 11,375 women in the meta-analysis. Results Systematic use of the Dopp ler umbilical artery velocimetry had no statistically significant effe ct on perinatal deaths in unselected populations (odds ratio [OR] 1.28 ; 95% confidence interval [CI] 0.61-2.67), low risk populations (OR 0. 51; 95% CI 0.20-1.29) or overall for the four trials (OR 0.90; 95% CI 0.50-1.60); nor was there any significant effect on stillbirths (globa l OR 0.94; 95% CI 0.42-1.98). However, the number of' participants rem ain insufficient and further information is required to arrive at a de finite conclusion on the absence of effect. The meta-analysis showed n o significant difference between the Doppler groups and the control gr oups for antenatal hospitalisation, obstetric outcome or perinatal mor bidity. Conclusion Based on the results of the published trials, routi ne use of the umbilical Doppler cannot be recommended.