title: Parity and secondary progression in multiple sclerosis.
abstract: BACKGROUND
  Pregnancy has a well-documented effect on relapses in multiple sclerosis (MS), whereas little is known about the impact of pregnancy and childbirth on the risk of secondary progression.
  
  
  OBJECTIVE
  To investigate the association of parity and secondary progression in women with MS.
  
  
  METHODS
  The association of the number of births and secondary progression was studied in a hospital-based cohort of 277 women with MS. Data were analysed in a multivariable logistic regression model, with adjustment for possible confounders.
  
  
  RESULTS
  Parity was not independently associated with secondary progression, while the factors disease duration (OR per year increase: 1.05, 95% CI 1.03 to 1.09) and use of immunomodulatory treatments (OR 0.23, 95% CI 0.08 to 0.65) were independently associated with secondary progression.
  
  
  CONCLUSIONS
  We found no evidence that parity influences the risk of secondary progression in MS. Further population-based studies on the association of pregnancy and childbirth on the long-term prognosis of MS are needed.
authors.affiliation: Department of Neurology, University Medical Center Groningen, Postbus 30.001, 9700RB Groningen, The Netherlands. m.w.koch@neuro.umcg.nl
authors.forename: M
authors.initials: M
authors.lastname: Koch
authors.forename: M
authors.initials: M
authors.lastname: Uyttenboogaart
authors.forename: D
authors.initials: D
authors.lastname: Heersema
authors.forename: C
authors.initials: C
authors.lastname: Steen
authors.forename: J
authors.initials: J
authors.lastname: De Keyser
mesh_terms: D000328:Adult; D017668:Age of Onset; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D020528:Multiple Sclerosis, Chronic Progressive / Q000175:diagnosis*; D015999:Multivariate Analysis; D009460:Neurologic Examination; D010298:Parity; D011247:Pregnancy; D012307:Risk Factors