[Arachnoid cyst and pregnancy. Report of a case].

The arachnoid cysts are intracranial liquid collections with a congenital etiology. It is necessary to establish the absence of bibliographical information about this disease and its relation with pregnancy. A case is presented related to the treatment of a nineteen year old pregnant patient with a 31 week pregnancy and a history of arachnoid cysts with convulsions as the main symptom.