The incidence of pregnancy-related stroke: A systematic review and meta-analysis

Background Stroke risk is increased during pregnancy, but estimates of pregnancy-related stroke incidence vary widely. Aims A systematic review and meta-analysis was conducted to assess the incidence of stroke during pregnancy and the puerperium. Ovid Medline, EMBASE, and ISI Web of Science were searched for studies published between 1990 and January 2017 reporting stroke incidence during pregnancy and postpartum, from defined pregnancy populations. Pooled analyses were conducted using a random effects approach and expressed as an incidence rate per 100,000 pregnancies, with 95% confidence intervals. Subgroup analyses of stroke type and timing were conducted. Summary of review Eleven studies met inclusion criteria. Variation in estimated rates was noted based on geography and study methodology. The pooled crude rate of pregnancy-related stroke was 30.0 per 100,000 pregnancies (95% confidence interval 18.8-47.9). The pooled crude rates from nonhemorrhagic stroke (arterial and cerebral venous sinus thrombosis) were 19.9 (95% confidence interval 10.7-36.9) and from hemorrhage 12.2 (95% confidence interval 6.4-23.2) per 100,000 pregnancies. For studies separately reporting cerebral venous sinus thrombosis, the rates were roughly equal between ischemic stroke (12.2, 95% confidence interval 6.7-22.2), cerebral venous sinus thrombosis (9.1, 95% confidence interval 4.3-18.9), and hemorrhage (12.2, 95% confidence interval 6.4-23.2). The crude stroke rate for antenatal/perinatal stroke was 18.3 (95% confidence interval 11.9-28.2), and for postpartum stroke was 14.7 (95% confidence interval 8.3-26.1). Conclusions Stroke affects 30.0 per 100,000 pregnancies, with ischemia, cerebral venous sinus thrombosis, and hemorrhage causing roughly equal numbers and with highest risk peripartum and postpartum. Organized approaches to the management of this high-risk population, informed by existing evidence from stroke and obstetrical care are needed.