Fetal Behavioural Responses to Maternal Voice and Touch

Although there is data on the spontaneous behavioural repertoire of the fetus, studies on their behavioural responses to external stimulation are scarce.

The aim of the current study was to measure fetal behavioural responses in reaction to maternal voice; to maternal touch of the abdomen compared to a control condition, utilizing 3D real-time (4D) sonography. Behavioural responses of 23 fetuses (21st to 33rd week of gestation; N = 10 in the 2nd and N = 13 in the 3rd trimester) were frame-by-frame coded and analyzed in the three conditions.

Results showed that fetuses displayed more arm, head, and mouth movements when the mother touched her abdomen and decreased their arm and head movements to maternal voice. Fetuses in the 3rd trimester showed increased regulatory (yawning), resting (arms crossed) and self-touch (hands touching the body) responses to the stimuli when compared to fetuses in the 2nd trimester.

In summary, the results from this study suggest that fetuses selectively respond to external stimulation earlier than previously reported, fetuses actively regulated their behaviours as a response to the external stimulation, and that fetal maturation affected the emergence of these differential responses to the environment.