Intrapartum umbilical artery Doppler velocimetry is a poor predictor of adverse perinatal outcome

OBJECTIVE To evaluate the value of intrapartum umbilical artery Doppler velocimetry for predicting adverse perinatal outcomes. DESIGN Meta-analysis of studies to assess a diagnostic test. DATA SOURCES Computerized search of MEDLINE from 1966 to 1997, and hand searches of the bibliographies of relevant articles and the authors' personal files. STUDY SELECTION Masked articles were evaluated independently by two reviewers for inclusion and methodological quality. Studies were included that assessed umbilical artery Doppler velocimetry, performed on pregnant women during labour, and reported adverse perinatal outcomes. DATA EXTRACTION Data for each outcome by diagnostic test result were abstracted into 2 × 2 tables independently by two reviewers, under masked conditions. MAIN OUTCOME MEASURES Pooled likelihood ratio of a positive test (LR + , 95% CI) for the perinatal outcomes Apgar score < 7 at 1 and 5 min, small for gestational age, fetal heart rate abnormality, umbilical artery acidosis at delivery, and cesarean section for fetal distress. MAIN RESULTS Eight studies, published between 1989 and 1997, met the inclusion criteria. They included 2700 women in unselected or low-risk and/or high-risk populations. The Doppler method used was continuous wave in seven studies and pulsed wave in one study, with single, as opposed to serial, testing in all but one study. The measurement used was pulsatility index in three studies (cutoff levels of > 1.2 or > 2 SD) and systolic/diastolic ratio in five studies (cutoff levels of > 2.6 or > 3). Blinding of test results was reported for six studies. From four studies (1767 women), the LR + for Apgar score < 7 at 1 min was 2.5 (1.7-3.7)* (change in risk with a positive test from 5 to 12%). From four studies (987 women), the LR + for Apgar score < 7 at 5 min was 1.3 (0.4-4.1) (change in risk 1.4 to 1.8%). From five studies (711 women), the LR + for small for gestational age was 3.4 (2.3-5.1)* (change in risk 9 to 26%). From two studies (643 women), the LR + for fetal heart rate abnormality was 1.4 (0.9-2.1) (change in risk 21 to 27%). From four studies (825 women), the LR + for umbilical artery acidosis was 1.6 (1.1-2.5)* (change in risk 15 to 22%). From four studies (701 women), the LR + for cesarean section for fetal distress was 4.1 (2.7-6.2)* (change in risk 8 to 26%). The pooled likelihood ratios of a negative test for all outcomes ranged from 0.9 to 1.1 and included unity. CONCLUSION Intrapartum umbilical artery Doppler velocimetry can identify pregnancies at slightly increased risk for low Apgar score at 1 min, small for gestational age infants, umbilical artery acidosis and cesarean delivery for fetal distress, but, in general, is a poor predictor of adverse perinatal outcome.