Rolling up of baby’s ears may be caused by congenital developmental abnormality, squeezing in the uterus, sleep compression and other reasons. 1. Congenital developmental abnormality: If the outer ear is deformed, such as round ear, ring-shrunk ear, etc., it may be due to congenital developmental abnormality or heredity that causes the baby’s ears to roll up. 2. Squeezing in the uterus: Since the baby’s ears are close to the uterine wall before birth, it may lead to pressure on the ears, so the baby’s ears roll up after birth. 3. Compression during sleep: Since the cartilage of infants within 3 months of age is soft in texture, if it is compressed during sleep, it can lead to a change in shape, resulting in a rolled up ear. If there is any deformity in the baby’s ears, you can go to the hospital for examination and follow the doctor’s instructions for treatment.