Indicators of fetal engagement with the environment

Abstract

Fetal behaviour provides a non-invasive window into early fetal development, reflecting the maturation of sensory and motor systems. This thesis investigates the developmental trajectory of spontaneous and stimulus-evoked behaviours across late gestation (33–37 weeks) to identify behavioural indicators of selective sensory engagement. Secondary analyses were conducted on high-resolution ultrasound recordings using a systematic behavioural measurement framework, incorporating standardised coding of fetal behavioural states (FBS), fetal body movements (FBM), and fetal eye movements (FEM) to enhance observational reliability and analytical rigor. Quantitative analysis, including Dynamic Time Warping (DTW), was employed to distinguish baseline behavioural activity from responses elicited by controlled auditory and visual stimuli. Study 1 (N = 57) investigated patterns of FBM and FEM to determine whether observed behaviours reflected spontaneous activity or environmentally driven engagement. Results indicated that from approximately 33 weeks’ gestation onward, FEM classifications increasingly aligned with behavioural markers of environmental engagement, suggesting progressive maturation of sensory–behavioural integration. Study 2 (N = 24) examined fetal behavioural responses to musical stimuli varying in timbre (string versus piano) and harmonic modality (major versus minor chords). We observed distinct patterns of structured FEM and FBM across auditory conditions, indicating selective behavioural modulation in response to specific acoustic properties.

The findings from this cross-sectional study suggest that late-gestation fetuses demonstrate emerging capacities for selective engagement with environmental stimuli before birth. This research advances understanding of prenatal sensory and perceptual processing and supports refinement of fetal behavioural frameworks, with implications for clinical monitoring and foundational research into early perceptual learning.