Prenatal behavioral contagion through maternal yawning and fetal resonance

Here, we tested whether prenatal yawning may also be modulated by maternal behavior. Using ultrasound recordings of fetal facial activity combined with controlled elicitation of maternal yawning, we show that fetal yawning selectively increases following maternal yawns but not during non-contagious control conditions. Temporal analyses reveal structured coordination between maternal and fetal yawning, and machine-learning classification identifies shared kinematic signatures across maternal and fetal yawns. These findings suggest that fetal yawning might also be embedded within a dyadic sensorimotor context in which maternal behavior shapes fetal expression, suggesting that forms of behavioral resonance and embodied alignment precede birth and contribute to the early foundations of social attunement.