The greater vestibule is an inner ear malformation that is part of the greater vestibular aqueduct syndrome. If the first child has a large vestibule, the second child does not necessarily have a large vestibule. Because vestibular aqueduct syndrome is an autosomal recessive disorder, a large vestibule in the first child proves that both spouses carry the gene that causes the disease. However, whether or not a large vestibule develops in the second child has nothing to do with the presence or absence of the disease in the first child, but the prevalence of the disease is higher than that of a normal person. If you are currently pregnant with your second child and are worried about the appearance of grand mal, it is recommended that you go to the hospital in time to do amniocentesis to clarify the chromosomal situation and genetic situation, and do regular labor and delivery tests to understand the development of the embryo, according to the examination, if you find that the development of the embryo is abnormal, you need to terminate the pregnancy in a timely manner. Emotions should be relaxed during pregnancy, avoid anxiety and tension, once any problems are found, we should seek timely medical treatment, and targeted treatment under the guidance of professional physicians.