Fetal neurobehavior and consciousness: a systematic review of 4D ultrasound evidence and ethical challenges.
Journal of perinatal medicine November 25, 2025 Mochammad Besari Adi Pramono, Wiku Andonotopo, Muhammad Adrianes Bachnas et al.
A systematic review of 74 studies (23 high-quality) examined whether fetal behaviors observed via 4D ultrasound—such as yawning, hand-to-face movement, and startle responses—indicate conscious awareness. Behaviors increased in complexity between 24–34 weeks gestation and aligned with neurodevelopmental milestones like thalamocortical connectivity and cortical folding. However, no study provided definitive evidence linking these behaviors to conscious experience. Artificial intelligence applications enhanced pattern recognition but lacked external validation. The authors argue that fetal behavior may reflect increasing neural integration but should not be equated with awareness, and interpretations must avoid anthropomorphic assumptions while respecting ethical limits and maternal autonomy.