[Computerized cardiotocography analysis of fetal heart response to acoustic stimulation].

PURPOSE to study the effect of acoustic stimulation in the fetal cardiac response, according to parameters from computerized cardiotocography in low risk pregnancies. METHODS twenty low risk pregnant women were included in the study, according to the following criteria: age over 18; single gestation, living fetus; gestational age between 36 and 40 weeks; amniotic liquid index over 8.0 cm and absence of fetal malformation. Cases with post-natal diagnosis of fetal anomaly were excluded. Computerized cardiotocography was performed for 20 minutes, before and after fetal acoustic stimulation. Results were analyzed by the t test for dependent samples, with significance level at p<0.05. RESULTS acoustic stimulation was successfully performed in all cases analyzed. By the analysis of the cardiotocographic parameters, there was no significant difference when the pre and post-stimulation parameters were compared: average number of fetal movements per hour (55.6 versus 71.9, p=0.1); mean basal fetal heart rate (FHR) (135.2 versus 137.5 bpm, p=0.3); mean FHR increases>10 bpm (6.5 versus 6.8, p=0.7); mean FHR increases>15 bpm (3.8 versus 4.3, p=0.5); mean duration of high FHR variation episodes (11.4 versus 10.9 min, p=0.7); mean duration of low FHR variation episodes (2.5 versus 1.1 min, p=0.2), and mean short-term variation (10.6 versus 10.9 ms, p=0.6). CONCLUSIONS in low risk gestations at term, computerized cardiotocography has not evidenced differences in the FHR parameters after the fetal sonic stimulation.