title: Influenza virus infection in pregnancy: a review.
abstract: BACKGROUND
  Influenza virus infection is very common and a significant cause of morbidity and mortality in specific populations like pregnant women. Following the 2009 pandemic, several reports on the effects of influenza virus infection on maternal health and pregnancy outcome have been published. Also the safety and efficacy of antiviral treatment and vaccination of pregnant women have been studied. In this review, we have analyzed and summarized these data.
  
  
  OBJECTIVE
  To provide information on the influence of influenza virus infection during pregnancy on maternal health and pregnancy outcome and on the effect of treatment and vaccination.
  
  
  METHODS
  We have searched Medline, Embase and the Cochrane Library. We used influenza, influenz*, pregnancy and pregnan* as search terms.
  
  
  METHODS
  In total, 294 reports were reviewed and judged according to the STROBE guidelines or CONSORT statement. In all, 100 studies, published between 1961 and 2015, were included.
  
  
  RESULTS
  Compared to the general population, pregnant women are more often hospitalized and admitted to an intensive care unit due to influenza virus infection. For hospitalized patients, increased rates of preterm birth and fetal/neonatal death are reported. Early treatment with oseltamivir is associated with a reduced risk of severe disease. Vaccination of pregnant women is safe and reduces maternal and neonatal morbidity.
  
  
  CONCLUSIONS
  There is level 2b evidence that maternal health and pregnancy outcome can be severely affected by influenza virus infection. Antiviral treatment may diminish these effects and vaccination protects pregnant women and neonates from infection (level of evidence 2b and 1b, respectively).
authors.affiliation: Perinatal Center, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Wouter J
authors.initials: WJ
authors.lastname: Meijer
authors.affiliation: Department of Obstetrics and Gynecology, Ikazia Hospital, Rotterdam, the Netherlands.
authors.forename: Aleid G A
authors.initials: AG
authors.lastname: van Noortwijk
authors.affiliation: Perinatal Center, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Hein W
authors.initials: HW
authors.lastname: Bruinse
authors.affiliation: Department of Virology, Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Annemarie M J
authors.initials: AM
authors.lastname: Wensing
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use; D005260:Female; D006760:Hospitalization; D006801:Humans; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D011256:Pregnancy Outcome; D014611:Vaccination
chemical_list: D000998:Antiviral Agents
keywords: Influenza; maternal health; pregnancy; treatment; vaccination