Relationship between eye movement period and micturition in newborn infants differs from that of human fetuses at term

Aim: To investigate the relationship between the onset of eye movement periods and micturition in human fetuses and in neonates with the intention of clarifying the transition in relationship during the perinatal period. Methods: Data were acquired during 1-4 days and/or 1 month (29-33 days) from 6 normal neonates born at term. Eye movements, crying, and eye open periods were observed with a video recorder until micturition occurred. In 29 term fetuses, the time lag between the onset of an eye movement period and micturition was measured by real-time ultrasound instruments. Results: The time lag between the onset of an eye movement period and micturition in neonates (2 minutes; range, 0-57 minutes) was significantly (P=0.027) different from the time lag for fetuses (14 minutes; range, 2-32 minutes) and the frequency of micturition occurring within 8 minutes (33%) was significantly lower (P = 0.017) than that seen for term fetuses (72%). Conclusion: The relationship between the onset of an eye movement period and micturition is different in term human fetuses and neonates of less than 1 month of age. This suggests that the neuronal relationship among brain centers for micturition, rapid-eye-movement sleep, and awakening is dramatically altered perinatally.