Intrauterine growth retardation—a prospective study of the diagnostic value of real-time sonography combined with umbilical artery flow velocimetry

This study was undertaken to evaluate the role of umbilical artery flow velocimetry combined with sonographic estimation of fetal weight, head circumference to abdominal circumference ratio, femur length to abdominal circumference ratio, and qualitative determination of amniotic fluid volume as a comprehensive test for the detection of intrauterine growth retardation (IUGR). The following cutoff values were used to indicate abnormal test results: 1) umbilical artery peak systolic to end-diastolic ratio (S/D) above 3, 2) estimated fetal weight below the tenth percentile for gestational age, 3) head circumference to abdominal circumference ratio more than 2 SD above the mean for gestational age, 4) femur length to abdominal circumference ratio above 23.5%, and 5) qualitative amniotic fluid volume less than 2 cm. The study population consisted of 127 patients referred with a clinical suspicion of IUGR. Forty-five infants (35%) were small for gestational age. None of these five tests were uniformly successful in identifying growth-retarded infants. Overall, the best predictor appeared to be estimated fetal weight below the tenth percentile for gestational age, which correctly identified 39 of the 45 IUGR infants (sensitivity 87%, specificity 87%). The sensitivity of this test was nearly twice that of any other test. AH indices performed similarly in predicting the non-IUGR infant (range of specificities 87–98%).