title: Pregnancy increases stroke risk up to 1 year postpartum and reduces long-term risk.
abstract: BACKGROUND
  : The incidence of stroke in pregnant women is low but trending upward. There are few studies of the topic in women of Asian ethnicity.
  
  
  OBJECTIVE
  We aim to evaluate stroke risk in Asian women during and after pregnancy.
  
  
  METHODS
  : Using the Taiwan National Health Insurance database, we designed a retrospective study that included 18-45-year-old pregnant women between the years 2000 and 2010. We selected a 1:1 age-matched control group of non-pregnant women. The endpoint was any type of stroke during pregnancy or the postpartum period; otherwise, the patients were tracked until 31 December 2010.
  
  
  METHODS
  : The risk factors for stroke were found using Cox proportional regression to calculate the hazard ratio (HR) with a 95% CI compared with the control group.
  
  
  RESULTS
  : The incidence of stroke within 1 year postpartum was 71/100,000. The risk of postpartum stroke within 1 year was an HR of 1.208 (95% CI: 1.001-5.129). The occurrence of stroke was associated with hypertension, diabetes mellitus, coagulation disorders, migraine, obesity, cerebrovascular malformation and parity. Women with third and fourth parity carried increased risks of 13.3% and 2.5%, respectively, compared with first parity women. In long-term follow-ups, stroke risk was significantly lower, with an adjusted HR of 0.362 (95% CI: 0.269-0.489).
  
  
  CONCLUSIONS
  The risk of stroke was elevated during the first year postpartum, but lower in subsequent years. Stroke risk increased in multiparous (≥3) women. Physicians should be on alert for pregnancy complications and ensure appropriate management to prevent postpartum stroke.
authors.affiliation: From the Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.|Graduate Institute of Biomedical Informatics, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chun-An
authors.initials: CA
authors.lastname: Cheng
authors.affiliation: From the Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Jiunn-Tay
authors.initials: JT
authors.lastname: Lee
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Hung-Che
authors.initials: HC
authors.lastname: Lin
authors.affiliation: From the Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Hui-Chen
authors.initials: HC
authors.lastname: Lin
authors.affiliation: Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.|Department of Health Duties and Chronic Epidemiology, School of Public Health, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Chi-Hsiang
authors.initials: CH
authors.lastname: Chung
authors.affiliation: Department of Health Duties and Chronic Epidemiology, School of Public Health, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Fu-Huang
authors.initials: FH
authors.lastname: Lin
authors.affiliation: Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Chang-Huei
authors.initials: CH
authors.lastname: Tsao
authors.affiliation: Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Yung-Fu
authors.initials: YF
authors.lastname: Wu
authors.affiliation: Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.|Department of Health Duties and Chronic Epidemiology, School of Public Health, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Wu-Chien
authors.initials: WC
authors.lastname: Chien
authors.affiliation: Graduate Institute of Biomedical Informatics, Taipei Medical University, Taipei, Taiwan.
authors.forename: Hung-Wen
authors.initials: HW
authors.lastname: Chiu
mesh_terms: D000293:Adolescent; D000328:Adult; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D010298:Parity; D049590:Postpartum Period; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000453:epidemiology* / Q000209:etiology; D011644:Puerperal Disorders / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult