Primary and Secondary Intracerebral Hemorrhage in Pregnant and Nonpregnant Young Adults by SMASH‐UP Criteria

Abstract

Background Intracerebral hemorrhage (ICH) is a major cause of maternal morbidity, but its pathophysiology is poorly characterized. We investigated characteristics of pregnancy‐associated ICH (P‐ICH), compared with ICH in similar aged nonpregnant adults of both sexes. Methods and Results We performed a retrospective analysis of 134 adults aged 18 to 44 years admitted to our center with nontraumatic ICH from January 1, 2012, to December 31, 2021. We compared ICH characteristics among 3 groups: those with P‐ICH (pregnant or within 12 months of end of pregnancy); nonpregnant women; and men. We categorized ICH pathogenesis according to a modified scheme, SMASH‐UP (structural, medications, amyloid angiopathy, systemic, hypertension, undetermined, posterior reversible encephalopathy syndrome/reversible cerebral vasoconstriction syndrome), and calculated odds ratios and 95% CIs for primary (spontaneous small‐vessel) ICH versus secondary ICH (structural lesions or coagulopathy related), using nonpregnant women as the reference. We also compared specific ICH pathogenesis by SMASH‐UP criteria and functional outcomes between groups. Of 134 young adults with nontraumatic ICH, 25 (19%) had P‐ICH, of which 60% occurred postpartum. Those with P‐ICH had higher odds of primary ICH compared with nonpregnant women (adjusted odds ratio, 4.5 [95% CI, 1.4–14.7]). The odds of primary ICH did not differ between men and nonpregnant women. SMASH‐UP pathogenesis for ICH differed significantly between groups ( P <0.001). While the in‐hospital mortality rate was lowest in the P‐ICH group (4%) compared with nonpregnant women (13%) and men (24%), 1 in 4 patients with P‐ICH were bedbound and dependent at the time of discharge. Conclusions In our cohort of young adults with ICH, 1 in 5 was pregnancy related. P‐ICH differed in pathogenesis compared with non–pregnancy‐related ICH in young adults, suggesting unique pathophysiology.