Maturation of human fetal responses to airborne sound in low- and high-risk fetuses

• Published in: Early human development 2000-06, Vol.58 (3), p.179-195
• Main Authors: Kisilevsky, Barbara S, Pang, LiHui, Hains, Sylvia M.J
• Format: Article
• Language: English
• Subjects: Acoustic Stimulation; Auditory; Biological and medical sciences; Body movements; Embryology: invertebrates and vertebrates. Teratology; Female; Fetal Movement; Fetus; Fetus - physiology; Fundamental and applied biological sciences. Psychology; Gestational Age; Heart rate; Heart Rate, Fetal; Humans; Infant, Newborn; Infant, Premature; Male; Organogenesis. Fetal development; Organogenesis. Physiological fonctions; Pregnancy; Risk Factors; Sound
• ISSN: 0378-3782; 1872-6232
• DOI: 10.1016/S0378-3782(00)00075-X

The purpose of the study was to characterize the onset and maturation of airborne sound-elicited responses in low- and high-risk preterm fetuses. In Study 1, a total of 91 low-risk fetuses at 27, 30, 33, and 36 weeks GA received three sound trials at 90, 100, 105 and 110 dB and three no-stimulus control trials. The onset of cardiac acceleration and body movement responses occurred at 30 weeks GA. Maturation of the cardiac response was observed with a decrease in threshold from 105–110 dB at 33 weeks GA to 100–105 dB at 36 weeks GA. In Study 2, the procedure was similar except that the 43 high-risk fetuses at 27, 30 and 33 weeks GA did not receive sounds at 90 dB. For the high-risk fetuses, the onset of cardiac and motor responses also occurred at 30 weeks GA. At 33 weeks GA, those high-risk fetuses subsequently born at term showed an increased magnitude of the cardiac acceleration response compared to low-risk fetuses. The results indicate that both low- and high-risk fetuses begin responding to sounds at the same gestational age. Differential responses observed over gestation in the high-risk group most likely indicate differential functional development of the auditory-response system.