The acoustic stimulation test and antenatal cardiotocography as diagnostic tools in high risk pregnancies

SummaryA prospective random allocation clinical trial was undertaken to compare standard antenatal cardiotocography with the fetal acoustic stimulation test. Two hundred and twenty-five patients with high risk pregnancies at term had either standard cardiotocography (group I) or an acoustic stimulation test (group II). The incidences of non-reactive tests was 10 per cent in group I and 15 per cent in group II did not differ statistically. Fetal distress occurred during labour in 13 per cent in patients with reactive cardiotocograms and 75 per cent if the record was unreactive (P < 0˙001); and in 12 per cent with reactive and 81 per cent with non-reactive acoustic stimulation tests (P < 0 ˙001). Standard antenatal cardiotocography and the acoustic stimulation test are equally valuable in detecting fetal distress in high risk term pregnancies. The acoustic stimulation test offers the advantage of reducing testing time and can be used to confirm a non-reactive standard test.