If the left lateral ventricle of the fetus is simply widened and is not associated with other abnormalities, regular checkups are sufficient. If the left lateral ventricle continues to widen, it should be combined with amniocentesis or other prenatal examinations to rule out the possibility of abnormal development of the fetus. If the widening of the left lateral ventricle does not exceed 1 cm in the middle and late stages of pregnancy, and there are no abnormalities such as strong light spots in the left ventricle, abnormal intestinal echogenicity, or widening of the renal pelvis, the widening of the left lateral ventricle belongs to simple lateral ventricle widening, and most of the fetuses will absorb the widening on their own and gradually return to normal, and regular checkups will be sufficient. If the left lateral ventricle of the fetus continues to widen and has exceeded 1 cm, and the possibility of abnormal development of the fetus cannot be ruled out, fetal magnetic resonance imaging, amniocentesis or other prenatal examinations should be performed to check whether the fetus has abnormal brain tissue and structure, or chromosomal diseases. If the examination is clear that the fetus is developing abnormally, you should cooperate with the specialized doctor to take appropriate measures as soon as possible. Once the examination reveals that the left lateral ventricle of the fetal brain is widened, it is recommended to take into account the diagnostic advice of professional doctors to determine whether to carry out the next step of examination and treatment.