3 weeks old children still wet the bed, if only 1 occasional bedwetting, most of them are due to daytime over-excitement. Because the pediatric nervous system is not very well developed, especially in the 2 hours before bedtime is still very excited, after sleep, it is easy to appear bedwetting phenomenon, this situation parents do not need to worry about, do not need treatment. If the 3-week-old child long-term bedwetting, it is possible that the habit has not been developed, parents did not regularly wake up the child at regular intervals to develop a reflex to urinate. Parents can reduce the intake of fluids, liquids and water-rich fruits for dinner, such as less porridge, and try not to drink water within 2 hours before bedtime, and empty the urine before bedtime, and in the short term, you can wake up the child at regular intervals during the night, so that the child will have a reflex to urinate, which gradually reduces the number of bedwetting, and can be restored. If it is caused by congenital sacrococcygeal spina bifida congenital disease, you need to take the child to the hospital to check the severity of the disease, under the guidance of the doctor to give further treatment.