OBJECTIVE Intracerebral hemorrhage during pregnancy or puerperium (pICH) is one of the leading causes of maternal death worldwide. However, limited epidemiological data exist on the etiology and outcomes of pICH, which are required to guide prevention and treatment. METHODS A retrospective nationwide cohort study and a nested case-control study were performed in Finland for 1987-2016. We identified women with incident pICH by linking the Medical Birth Register (MBR) and the Hospital Discharge Register (HDR). The clinical details were collected from patient records. Three matched controls with a pregnancy without ICH were selected for each case from the MBR. RESULTS In total, 49 pICH cases were identified. Half of these cases occurred during pregnancy, and the other half during peripartum and puerperium. Based on SMASH-U (structural vascular lesion, medication, amyloid angiopathy, systemic disease, hypertension, undetermined) classification, 35.4% of the patients had a systemic disease, most commonly preeclampsia, eclampsia, or HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome; 31.3% had a structural vascular lesion; 31.3% had undetermined etiology; and one patient (2.1%) had hypertension. The most important risk factor was hypertensive disorders of pregnancy (HDPs; odds ratio = 3.83, 95% confidence interval = 1.60-9.15), occurring in 31% of the cases. Maternal mortality was 12.5%, and 20.9% of the surviving women had significant disability (modified Rankin Scale = 3-5) 3 months after pICH. Women with systemic disease had the worst outcomes. CONCLUSIONS Even in a country with a comprehensive pregnancy surveillance system, the maternal mortality rate for pICH is high, and the sequelae are severe. Early recognition and treatment of the key risk factor, HDPs, are crucial to help prevent this serious pregnancy complication.