title: Maternal outcomes in pregnancies affected by varicella zoster virus infections: population-based study on 7.7 million pregnancy admissions.
abstract: OBJECTIVE
  Previous estimates of the incidence of varicella zoster virus (VZV) pneumonia and maternal death associated with VZV infection among the pregnant population have varied considerably and been based predominantly on reports from case series. We sought to measure the incidence of VZV-related morbidity and mortality to provide more representative population estimates.
  
  
  METHODS
  We carried out a large cohort study on all births using the United States Healthcare Cost and Utilization Project-Nationwide Inpatient Sample database between 2003 and 2010. Descriptive statistics were used to measure baseline characteristics and outcomes of women with VZV infection. Multivariate logistic regression analyses were used to identify risk factors for the development of VZV-related morbidity and mortality.
  
  
  RESULTS
  We identified 935 patients admitted for VZV infection among 7.7 million pregnancy admissions, representing an incidence of 1.21 cases/10 000 pregnancies (95% confidence interval [CI], 1.13-1.29). The incidence of VZV pneumonia was 2.5% (95% CI, 1.6-3.7). No maternal deaths were recorded during the 8-year study period. There were no significant risk factors identified for those who developed VZV pneumonia compared to those who had an uncomplicated VZV infection during pregnancy.
  
  
  CONCLUSIONS
  The incidence of VZV pneumonia and VZV infection associated with maternal death is significantly lower than previously estimated and may reflect better immunization and earlier interventions.
authors.affiliation: Department of Obstetrics and Gynecology, Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: Hui Jue
authors.initials: HJ
authors.lastname: Zhang
authors.forename: Valerie
authors.initials: V
authors.lastname: Patenaude
authors.forename: Haim A
authors.initials: HA
authors.lastname: Abenhaim
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006566:Herpesviridae Infections / Q000453:epidemiology*; D006801:Humans; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology*; D011256:Pregnancy Outcome; D014481:United States / Q000453:epidemiology
keywords: mortality; pneumonia; pregnancy; varicella zoster virus