Cerebral venous sinus thrombosis in the first trimester of pregnancy: A case report.

Cerebral venous sinus thrombosis (CVST) is a rare but potentially life-threatening cause of stroke, with increased incidence in pregnancy due to hypercoagulability, particularly during the third trimester and the postpartum period. First-trimester presentations are exceedingly rare. A 37-year-old woman, gravida 2, para 0, at 7 weeks of gestation, presented with severe, progressive headache, nausea, and vomiting. Her obstetric history was significant for intrauterine fetal demise (IUFD) at 22 weeks of gestation. Neurologic examination was nonfocal. Computed tomography venography (CTV), performed because magnetic resonance imaging (MRI) was contraindicated, demonstrated thrombosis of the left transverse and sigmoid sinuses extending into the left internal jugular vein. Therapeutic low-molecular-weight heparin resulted in clinical improvement. Evaluation during pregnancy was negative for acquired and inherited thrombophilias. The patient underwent an uncomplicated suction dilation and curettage and remained clinically stable on anticoagulation. This case illustrates the diagnostic challenges of CVST in early pregnancy and highlights CTV as a reliable alternative to MRI. Additionally, this case is notable for CVST presenting in the first trimester, a rare occurrence, with few cases reported in the literature. The combination of early pregnancy, prior IUFD without a known thrombophilia represents a unique risk factor constellation for CVST. Clinicians should maintain a high index of suspicion for CVST in patients presenting with severe, atypical headache in the first trimester, to enable timely diagnosis, anticoagulation, and optimized maternal outcomes.