[Diagnostic evaluation of fetal distress during pregnancy by a sound stimulation test].

A vibro-acoustic stimulus induces in the human fetus over 28 weeks of gestational age some modifications of the fetal heart rate. Absence of response, as a single test, has been used to suggest the diagnosis of fetal jeopardy (Read and Miller, Trudinger and Boylan). In this series, the pronostic value of the sound stimulation test (SST) was evaluated in association with the results of the widely used non stress test (NST). In 78 patients, 93 pathological NST, quantified by means of the Fischer's score, were assessed by SST. The results showed a good correlation between NST and SST : SST appears to be negative (no fetal response) in respectively 10%, 48% and 100% of NST tracings with Fischer score of 7, 6 or less than or equal to 5. Thus, when the basal Fischer score indicates fetal distress, no complementary test is needed (all 11 infants showed low Apgar score or acidosis). On the other hand, when the NST is less severely abnormal (score 6 or 7), the SST allows a good discrimination of the risk of neonatal distress. Among 62 cases explored less than one week before birth, a 27% (17/62) overall probability of neonatal depression (low Apgar score at 5 minutes and/or acidosis in the umbilical artery at birth) was noticed. The SST was interpreted as reactive in 44 cases of this group, with only 8 depressed neonates (18.2%). In the other 18 cases, a negative SST was followed by birth of 9 depressed infants (50%). The difference is statistically significant (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)