Influence of pregnancy in the behavior of diffuse gliomas: clinical cases of a French glioma study group.

Advances in the understanding of the natural history of diffuse low-grade gliomas and the optimization of their therapeutic management have allowed an improvement of their prognosis. Therefore, more and more young women harboring such gliomas now envision a pregnancy. However, relationships between gliomas and pregnancy are poorly known. We performed a retrospective review of all observed pregnancies in the adult female population of supra-tentorial hemispheric gliomas followed by a French glioma study group. Clinical, imaging and pathological findings were reviewed. In the present case studies, eight pregnancies in eight females were observed in a total of 443 adult females diagnosed between 1992 and 2007. Glioma was diagnosed before pregnancy in five patients and during pregnancy in three patients. In six cases, pregnancy appears as having possible negative interaction with the tumor, such as clinical worsening, tumor changes in imaging and histological findings. In two cases, pregnancy appears as having no effect in the natural history of the tumor. The present results suggest a possible negative interaction between pregnancy and diffuse gliomas. We thus propose informing the patient about the possible risks of tumor growth increase and of malignant transformation during pregnancy. In the presence of such a tumor, a pregnancy may reasonably be envisioned, but the benefit-to-risk ratio should be carefully weighed and discussed. If a pregnancy is decided, we thus advise performing a very close neurological follow-up with repeated control MRIs in addition to rigorous obstetrical monitoring.