ObjectiveTo establish the indications for surgical intervention, at the appropriate gestational duration, for brain tumors in pregnant women, and to evaluate any association pregnancy hormones may have with the rate of growth or development of complications of brain tumors.MethodsWe observed seven women with brain tumors associated with pregnancy in a series of 126,413 pregnancies from 1983 to 1995. One woman presented with symptoms of intracranial hypertension, and neurologic signs were the first symptoms in two other women. One woman presented with a sudden hemorrhagic lesion, and three had focal seizures. All were evaluated with computed tomography, magnetic resonance imaging, or both.ResultsSix of the seven women had surgery; the seventh was treated with radiotherapy because the neuroradiologic studies suggested a quickly growing brainstem glioma. Diagnoses were confirmed on histology in six women: two with meningiomas, two with ependymomas, and two with low-grade astrocytomas (one of these had multiple astrocytomas). Estrogen and progesterone receptors were studied in two cases (one meningioma and one astrocytoma) and were present in both.ConclusionManagement of brain tumors should be tailored to the individual patient. There may be a relation between pregnancy hormones and the rate of brain tumor growth mediated through specific intracellular receptors.