Newborns sleep legs are always bent mainly because of the continuation of maternal posture and cerebral hypoxia. 1. Continuation of the mother’s posture: due to the mother’s uterine space is small, the newborn has been kept in a state of curled up, which can cause the newborn contraction of muscle strength is strong, the extension of the muscle strength is weak, so the newborn sleep legs are always bent, which is a normal phenomenon, generally with the newborn’s growth and development, the legs will be slowly straightened. 2. Cerebral hypoxia: If the newborn at birth, because of asphyxia caused by cerebral hypoxia, so that the basal ganglia, thalamic nucleus or medial nucleus of the anomalies, resulting in the innervation of the lower limbs of the nervous system dysfunction, when the lower limbs of the muscle tension is too high, the newborn sleep legs will always be bent. Newborns sleeping legs are always bent, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.