FETAL BIOPHYSICAL PROFILE AND VIBRATORY ACOUSTIC STIMULATION IN HIGH-RISK PREGNANCIES

Objectives: To determine the influence of the non-stress test (NST) on the efficiency of the fetal biophysical profile (FBP) and to test the clinical usefulness of the FBP and its combination with vibratory aco ustic stimulation (VAS) in managing high-risk pregnancies. Methods: On e hundred twenty fetuses of preeclamptic patients were included in a p rospective study. Five standard variables of the FBP were observed ult rasonically following NST. In cases of nonreactive NST, external VAS w as applied and the FBP score calculated and compared with the FBP scor e before VAS. Results: Of 120 calculated FBPs, 102 (85%) had normal pr ofile scores before VAS and 104 (86.7%) after VAS. No statistically si gnificant difference was found. The sensitivity, specificity, and posi tive and negative predictive values of the FBP score in predicting poo r perinatal outcome were 94.7%, 94.40/0, 75% and 99%, respectively. VA S produced a high conversion (58.8%) of non-reactive NST to reactive f etal heart rate pattern. The false-negative rate of the FBP score was 9.8 per 1000, which did not increase after VAS. Conclusions: The effic iency of the FBP score was not significantly improved by VAS, although a high conversion of non-reactive to reactive NST was produced. The F BP with its three 'acute biophysical variables' was found to be an acc urate method of antepartum assessment even without an NST. The low inc idence of perinatal complications among patients with normal FBP score s, permits the conservative management of preterm high-risk pregnancie s.