Fetal heart rate after vibroacoustic stimulation

Objective: To define reference ranges for fetal heart rate (FHR) parameters after vibroacoustic stimulation (VAS) according to gestational age by determining the relationship between FHR and gestational age using a computerized analysis system. Methods: Data were analyzed from 3453 women using 10-minute observational recordings during nonstress testing (NST) and VAS testing. FHR parameters were analyzed according to gestational age. Results: All FHR parameters were related to gestational age except for mean baseline FHR, which did not vary significantly with gestational age. All other parameters followed trends similar to the NST results, except for decelerations. Conclusion: FHR parameters after VAS differed significantly according to gestational age. The results suggest that the gestational age of the fetus should be considered when interpreting FHR patterns after VAS. (C) 2009 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.