Onset and maturation of fetal heart rate response to the mother’s voice over late gestation
Article first published online: 20 APR 2010
© 2010 Blackwell Publishing Ltd
Volume 14, Issue 2, pages 214–223, March 2011
How to Cite
Kisilevsky, B. S. and Hains, S. M.J. (2011), Onset and maturation of fetal heart rate response to the mother’s voice over late gestation. Developmental Science, 14: 214–223. doi: 10.1111/j.1467-7687.2010.00970.x
- Issue published online: 20 APR 2010
- Article first published online: 20 APR 2010
- Received: 4 November 2009 Accepted: 21 January 2010
Background: Term fetuses discriminate their mother’s voice from a female stranger’s, suggesting recognition/learning of some property of her voice. Identification of the onset and maturation of the response would increase our understanding of the influence of environmental sounds on the development of sensory abilities and identify the period when speech and language might influence auditory processing.
Aim: To characterize the onset and maturation of fetal heart rate response to the mother’s voice. Methods: 143 fetuses from 29 to 40 weeks gestational age (GA) received a standardized protocol: no-sound pre-voice baseline (2 min), audio recording of their mother reading a story (2 min), no-sound post-voice (2 min). The voice was delivered 10 cm above the maternal abdomen at an average of 95 dB A; heart rate was recorded continuously.
Results: For data analyses, fetuses were categorized into four age groups: 29–31, 32–34, 35–37, and > 37 weeks GA. Onset of response to the mother’s voice occurred at 32–34 weeks GA. From 32 to 37 weeks GA, there was an initial heart rate decrease followed by an increase. At term, there was a response shift to an initial heart rate increase. The percentage of fetuses responding increased over gestation from 46% at 32–34 weeks GA to 83% at term.
Conclusion: A relatively long latency and sustained duration of the heart rate response suggest auditory processing, the formation of neural networks, above the level of the brainstem.