title: Selective uptake of influenza vaccine and pregnancy outcomes.
abstract: OBJECTIVE
  To describe the characteristics of pregnant women who accept the influenza vaccine and evaluate the relationship between vaccination and adverse pregnancy outcomes.
  
  
  METHODS
  Retrospective cohort study of women receiving prenatal care during the 2009-2011 influenza seasons. Vaccination status was ascertained through our perinatal record system and clinic vaccination logs. Pregnancy outcomes included a primary composite of miscarriage, fetal demise, preterm birth (PTB) <37 weeks and neonatal demise. Stratification and logistic regression were used to adjust for potential confounders.
  
  
  RESULTS
  Of 3104 eligible pregnant women, 1094 (35%) received the influenza vaccine. Women vaccinated were more likely to be older, obese, primiparae, and have medical complications or a prior PTB. In univariable analyses, flu vaccination was associated with increased adverse composite outcome and PTB. After multivariable adjustments, vaccination was no longer associated with adverse outcomes in women with medical complications but remained associated with adverse outcomes among those without known co-morbidity.
  
  
  CONCLUSIONS
  Vaccination was associated with an increased adverse composite outcome in pregnant women without identified co-morbidity but not those with co-morbidities. This association is likely due to selection bias, which should be considered in planning of observational studies of the impact of vaccination on pregnancy outcomes.
authors: Center for Women's Reproductive Health, University of Alabama at Birmingham, Birmingham, AL 35249, USA. jcantu@uabmc.edu
authors: Jessica
authors: J
authors: Cantu
authors: Joseph
authors: J
authors: Biggio
authors: Victoria
authors: V
authors: Jauk
authors: Luisa
authors: L
authors: Wetta
authors: William
authors: W
authors: Andrews
authors: Alan
authors: A
authors: Tita
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000209:etiology / Q000821:virology; D000328:Adult; D005260:Female; D005313:Fetal Death / Q000453:epidemiology / Q000209:etiology / Q000821:virology; D006801:Humans; D007234:Infant, Premature; D053118:Influenza A Virus, H1N1 Subtype / Q000472:pathogenicity; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D015983:Selection Bias; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines