THE EFFECT OF AN ABNORMAL UMBILICAL ARTERY DOPPLER ON THE MANAGEMENT OF FETAL GROWTH RESTRICTION - A SURVEY OF MATERNAL-FETAL MEDICINE SPECIALISTS WHO PERFORM FETAL ULTRASOUND

The purpose of this survey was to determine if an abnormal Doppler ultrasound scan of the umbilical artery alters the management of patients with fetuses with varying degrees of asymmetrical growth restriction remote from term. A survey was conducted of Maternal-Fetal Medicine specialists who practiced in the United States. Three cases of increasing severity of asymmetrical growth restriction (abdominal circumference > 2 standard deviations below the mean) were presented, each with a normal or abnormal Doppler of the umbilical artery. The estimated fetal weights were between the 15th and 25th centiles (Case 1), 10th and 15th centiles (Case 2), and less than the 10th centile (Case 3). Each physician was asked to respond to questions regarding the frequency (none, 2 weeks, 3 weeks, 4 weeks) of repeat ultrasound scans, the recommendation for maternal bed rest and its duration (none, 5 hours, 12 hours), and the choice of antepartum testing (none, non-stress test, non-stress test plus amniotic fluid index, contraction stress test, biophysical profile). A completed survey was returned by 199 of 900 (22%) Maternal-Fetal Medicine specialists who practiced in 33 of 50 states. Of respondents, 95% performed fetal ultrasound Over 98% of respondents repeated the ultrasound examination irrespective of the degree of growth restriction. Comparing the effect of a normal versus an abnormal Doppler for Case 1, there was a significant increase in the following: repeat ultrasound at the 2-week interval (46 vs. 68%, p < 0.00002); recommendation for maternal bed rest (55 vs. 80%, p < 0.00002); the duration of bed rest for 12 h (17 vs. 46%, p < 0.000001); recommendation for antepartum testing (82 vs. 96%, p < 0.00002); utilization of the contraction stress test (1 vs. 7%, p < 0.004); and the biophysical profile (17 vs. 27%, p < 0.02). Comparing the effect of a normal versus an abnormal Doppler on management for Case 2, there was a significant increase in the following: recommendation for maternal bed rest (80 vs. 89%, p < 0.02): duration of bed rest for 12 h (34 vs. 63%, p < 0.000001); and the recommendation for antepartum testing (95 vs. 99%, p < 0.04). Comparing the effect of a normal versus an abnormal Doppler on management for Case 3, the only significant increase was the recommendation for 12 h of bed rest (72 vs. 84%, p < 0.006). Comparison of the trends in management as the cases became more severe (Case 1 through Case 3) in the normal Doppler group demonstrated a significant increase in recommendation for repeat ultrasound at the 2-week interval (46 to 76%, p < 0.000001); recommendation for bed rest (55 to 92%, p < 0.000001); the duration of bed rest for 12 h (17 to 72%, p < 0.000001); recommendation for antepartum testing (82 to 100%, p < 0.000001); use of the contraction stress test (1 to 10%, p < 0.0004); and the biophysical profile (17 to 46%, p < 0.00009). Comparison of the trends in management as the cases became more severe (Case 1 through Case 3) in the abnormal Doppler group demonstrated a significant increase in recommendations for bed rest (80 to 96%, p < 0.000007); the duration of bed rest for 12 h (46 to 84%, p < 0.000002); and use of the biophysical profile (27 to 55%, p < 0.000001). An abnormal Doppler ultrasound scan of the umbilical artery appears to alter the recommendations for management of fetuses with varying degrees of growth restriction.