Strokes Associated With Pregnancy and Puerperium

Pregnancy-associated stroke is rare but is considered an important cause of morbidity and mortality in women of childbearing age. Previous studies dealing with the incidence of pregnancy-associated stroke have been performed using hospital-based, population-based, and nationwide methods, and most have been conducted in Western countries and Taiwan. The reported studies vary a great deal with respect to the reported causes and incidences of stroke, which could be partly attributed to selection biases because of population size or diagnostic imaging modality. In addition, racial and ethnic differences in stroke subtypes have been well recognized between Western and Asian populations. The aim of the present study was to elucidate the incidence and causes of pregnancy-associated strokes in Japanese women on a large scale in the era of magnetic resonance imaging (MRI). Methods This study was a retrospective analysis based on clinical chart review in 736 stroke teaching hospitals certified by the Japan Stroke Society. A nationwide survey was conducted in 2014 as an official project of the society. The target of the primary survey was all strokes occurring during pregnancy, delivery, and puerperium (within 6 weeks after delivery) that were treated in these hospitals within the 2-year period between January 2012 and December 2013. In the primary survey, all 736 training institutes were assigned to compile the number of patients with pregnancy-associated strokes treated in their own hospitals during this period. The results were emailed to the survey office without any clinical information. In the secondary survey, a web-based survey requesting detailed clinical information on each case without any personally identifying information was conducted. The clinical information included stroke type and time of stroke onset (gestational age or time after delivery), causes of hemorrhage, types of underlying cerebrovascular diseases (CVDs), types of obstetric systemic complications, time between symptom onset and initial computed tomography and MRI, and maternal prognoses. The Background and Purpose—The incidence and cause of strokes associated with pregnancy and the puerperium are still not fully understood. The aim of this study was to characterize pregnancy-related strokes in Japan using a large-scale survey with current imaging techniques. Methods—A retrospective analysis was conducted based on clinical chart reviews in 736 stroke teaching hospitals certified by the Japan Stroke Society between 2012 and 2013, using a web-based questionnaire requesting the detailed clinical course without any personally identifying information. The collection rate of this questionnaire was 70.5%, with 151 pregnancy-associated strokes extracted. Results—Hemorrhagic strokes were observed in 111 cases (73.5%), ischemic strokes in 37 (24.5%), and mixed type in 3 cases (2.0%). The estimated incidence of pregnancy-associated stroke was 10.2 per 100 000 deliveries. Major causes of hemorrhage were aneurysm (19.8%), arteriovenous malformation (17.1%), pregnancy-induced hypertension (11.7%), and HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count) (8.1%). Preexisting cerebrovascular diseases responsible for hemorrhage were detected in 59 cases (53.1%). Among the ischemic strokes, 28 (75.7%) were arterial and 9 (24.3%) were venous infarctions. The most frequent cause of arterial infarctions was reversible cerebral vasoconstriction syndrome. Hemorrhagic stroke showed much poorer prognosis than ischemic stroke. Conclusions—The incidence of pregnancy-associated stroke in Japan did not seem higher than that in other Asian and Western countries. The proportion of hemorrhagic stroke among Japanese women was much higher than that in white women. Preexisting cerebrovascular diseases and reversible cerebral vasoconstriction syndrome play a key role in hemorrhagic and ischemic stroke, respectively. (Stroke. 2017;48:276-282. DOI: 10.1161/STROKEAHA.116.014406.)