Journal of Research in Medical Sciences1735-199517420120405Oral contraceptive misuse as a risk factor for cerebral venous and sinus thrombosis82828282ENMohammadSaadatniaDepartment of Neurology, Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. saadatnia@med.mui.ac.irNedaNaghaviFarzadFatehiMohammadZareMarziehTajmirriahi2012040420120405Background: Consumption of oral contraceptive  pills (OCP) is a known risk factor for cerebral  venous and sinus thrombosis  (CVST) among  women. We determined  whether  misuse of OCP could increase  the  risk of CVST in women. Materials and Methods: A case-control study was conducted  from 2003 to 2007 on 64 female patients with CVST admitted to Al- Zahra medical center and 232 healthy age-matched female OCP users as controls. Patients and controls were interviewed and misuse of OCP was categorized to taking OCP for self-treatment of dysfunctional uterine bleeding, for family planning without physician consult, or for delaying menstruation in purpose of religious customs or traveling, and taking OCP in high dose during the preceding year. Results: Among 64 cases and 232 controls, 30 (46.9 %) and 63 (27.2 %), respectively, had a history of OCP misuse (Odds Ratio = 2.36, 95% Confidence Intervals = 1.33 to 4.18, P = 0.002). Also, using cyproterone  compound  (Diane) was more frequent in the CVST group (P<0.001). Multivariate analysis controlling for age, OCP misuse, type of OCP, and history of coagulopathy showed that OCP misuse (P<0.001) and using Diane as the OCP (P = 0.006) were both independently  associated with CVST. Conclusions: OCP misuse can be considered as an additional predisposing factor for CVST among women and partly responsible for larger proportion of female patients with CVST. These findings should alarm the healthcare system to create strategies controlling the inappropriate use of OCP among Iranian women.Key words: Cerebral venous and sinus thrombosis, misuse, oral contraceptive