Abstract
Meningiomas are often reported to be sensitive to progesterone, but it is not clear how pregnancy and childbirth affect this. A 41-year-old woman experienced two pregnancies and two deliveries. During the first pregnancy, her right visual acuity was impaired, but it recovered after delivery. However, during the second pregnancy, the right visual acuity was impaired again and did not recover after the second delivery. The magnetic resonance imaging revealed a right optic nerve sheath meningioma (ONSM). Surgical resection of the intracranial extension of the tumor was performed to prevent tumor invasion of the left optic nerve and optic chiasm. Pathological examination diagnosed meningioma with positive immunostaining for progesterone receptor. The present study provided clinical features of ONSM associated with pregnancy. ONSM may present with increased tumor growth and impaired vision with pregnancy.