When one side of the ventricle is widened by 10mm in a 27-week-old baby, if there is no chromosomal disease, the probability of complete absorption in the later stage is relatively high. Simply by virtue of the ventricular widening of 10mm, it is not possible to determine the specific cause, it is necessary to carry out screening for Down’s syndrome, to determine the existence of chromosomal abnormalities disease, if it exists, then the probability of self-absorption at a later stage is relatively small, if there is no chromosomal abnormality disease, with the development of the ventricular widening will be gradually reduced, and the excess cerebrospinal fluid will be gradually absorbed. When there exists 10mm widening of one side of the ventricle in a 27-week-old baby, it is recommended to go to the hospital in time to seek medical treatment, and under the guidance of the doctor, take reasonable methods to intervene and promote the normal development of the baby.