Association of Primary Intracerebral Hemorrhage With Pregnancy and the Postpartum Period.

Importance: Intracerebral hemorrhage (ICH) during pregnancy and the postpartum period results in catastrophic maternal outcomes. There is a paucity of population-based estimates of pregnancy-related ICH risk, including risk during the extended postpartum period. Objective: To evaluate ICH risk during pregnancy and an extended 24-week postpartum period in a population-level cohort and to determine fetal and maternal outcomes as well as demographic and comorbidity factors associated with ICH during pregnancy and post partum. Design, Setting, and Participants: This study used a cohort-crossover design in which patients serve as their own controls when no longer exposed (pregnant or post partum). Administrative data were obtained from all hospital admissions for New York, California, and Florida for a 7- to 10-year period. Participants included all women admitted for labor and delivery who were older than 12 years and did not have a prior diagnosis of ICH. Conditional Poisson regression models were used to evaluate ICH risk, and data were reported as rate ratios and 95% CIs. Data analysis was performed from August 2018 to February 2020. Exposures: Women were tracked using hospitalization records for the duration of pregnancy (40 weeks), for 24 weeks post partum, and for an additional 64 weeks when no longer exposed. Main Outcomes and Measures: Diagnosis of ICH during both 64-week observation periods was determined using validated International Classification of Diseases, Ninth Revision codes. Results: A total of 3 314 945 pregnant women were included (mean [SD] age, 28.17 [6.47] years; 1 451 780 white [43.79%], 474 808 black [14.32%], 246 789 Asian [7.44%], and 835 917 Hispanic [25.22%]). The risk of ICH was significantly higher during the third trimester (2.9 vs 0.7 cases per 100 000 pregnancies; rate ratio, 4.16; 95% CI, 2.52-6.86) and remained elevated during the first 12 weeks post partum (4.4 vs 0.5 cases per 100 000 pregnancies; rate ratio, 9.15; 95% CI, 5.16-16.23). Advanced maternal age (adjusted odds ratio [OR], 1.08; 95% CI, 1.05-1.10), nonwhite race (adjusted ORs, 2.44 [95% CI, 1.73-3.44] for black patients, 2.12 [95% CI, 1.34-3.35] for Asian patients, and 1.59 [95% CI, 1.12-2.26] for Hispanic patients), hypertension (adjusted OR, 2.02; 95% CI, 1.19-3.42), coagulopathy (adjusted OR, 14.17; 95% CI, 9.17-21.89), preeclampsia or eclampsia (adjusted OR, 9.23; 95% CI, 6.99-12.19), and tobacco use (adjusted OR, 2.83; 95% CI, 1.53-5.23) were independently associated with ICH during pregnancy and the postpartum period. Pregnancy-related ICH was associated with a higher risk of maternal (relative risk difference, 792.6; absolute risk difference, 0.18) and fetal (relative risk difference, 5.3; absolute risk difference, 0.03) death, compared with pregnancies without ICH. Conclusions and Relevance: These findings suggest that the risk of ICH is significantly higher during the third trimester of pregnancy and the first 12 weeks post partum. There are age and race disparities in ICH risk that are associated with devastating maternal and fetal outcomes. These data illustrate the critical need for continuous monitoring and aggressive management of ICH-associated risk factors. These findings suggest that extended postpartum monitoring of high-risk women may be warranted.