A widened lateral ventricle of 13mm may absorb on its own after birth. If the lateral ventricle continues to widen, there may be a disease that will not absorb after birth. Normally, the width of fetal ventricles is less than 10mm, and more than 10mm is considered widening of the ventricles, which is usually considered to be related to the increase of cerebrospinal fluid. Widening of the lateral ventricles can occur when the volume of cerebrospinal fluid in the brain is excessive due to untimely drainage of cerebrospinal fluid. If the fetal lateral ventricles widen by 13 mm and do not continue to widen, they may absorb on their own after birth. If the lateral ventricles continue to widen and enlarge and cannot be absorbed, it indicates hydrocephalus, and further examination with the doctor is needed to clarify whether it is caused by other diseases and to take timely treatment measures. Whether or not the 13mm widened lateral ventricles can be absorbed after birth mainly depends on whether or not the lateral ventricles have continued to widen. It is recommended that pregnant mothers undergo regular checkups and pay attention to whether or not the lateral ventricles have widened. Once abnormalities are detected, you should cooperate with your doctor for treatment as soon as possible.