Fetal lateral ventricles are normally invisible or less than 1.0, and a lateral ventricle of 1.0 at five and a half months of gestation requires continued follow-up and observation to detect fetal anomalies. Fetal lateral ventricles may widen physiologically or pathologically. Normally, the lateral ventricles are not visible at about 5 months of age or are less than 1 cm wide. If the lateral ventricles are simply widened, you can follow up and observe, and review the obstetric ultrasound and MRI. When the lateral ventricle is wider than 1.0cm, chromosomal and fetal structural abnormalities should be investigated, and further non-invasive DNA or amniocentesis should be performed to rule out the presence of chromosomal abnormalities in the fetus. If a fetal chromosomal or structural abnormality is detected and the lateral ventricle widening is greater than 1.5 cm, termination of pregnancy is usually recommended as an option.