title: Rheumatoid arthritis and outcomes in first and subsequent births based on data from a national birth registry.
abstract: OBJECTIVE
  To examine associations between rheumatoid arthritis (RA) and pregnancy outcomes in first and subsequent births.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Study based on data registered in the Medical Birth Registry of Norway from the period 1 December 1998 to 31 December 2009.
  
  
  METHODS
  Singleton births in women recorded with RA (n = 1496) and reference deliveries from the general population (n = 625,642).
  
  
  METHODS
  Outcomes of first and subsequent births were analyzed separately. First birth was defined as the first delivery of nulliparous women. Associations between RA and maternal and perinatal outcomes were assessed in logistic regression analyses and adjusted for maternal age at delivery, gestational age, smoking habits and for previous cesarean section when relevant.
  
  
  METHODS
  Maternal and perinatal outcomes.
  
  
  RESULTS
  Vaginal bleeding was observed more often among women with RA both in first pregnancy [adjusted odds ratio (aOR) 1.8, 95% CI 1.3-2.4] and in subsequent pregnancies (aOR 1.4, 95% CI 1.1-1.9). Elective cesarean section was more common among women with RA both in the first birth (aOR 2.0, 95% CI 1.4-2.8) and in subsequent births (aOR 1.5, 95% CI 1.2-2.0). Preterm delivery was more frequent among women with RA than the reference population in first pregnancy (aOR 1.5, 95% CI 1.1-2.0) and in subsequent pregnancies (aOR 1.5, 95% CI 1.1-1.9).
  
  
  CONCLUSIONS
  Complications and poor pregnancy outcomes were more often observed in women with RA and the greatest differences were observed in the first pregnancy.
authors.affiliation: National Service for Pregnancy and Rheumatic Diseases, Department of Rheumatology, Trondheim University Hospital, Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Marianne
authors.initials: M
authors.lastname: Wallenius
authors.forename: Kjell Å
authors.initials: KÅ
authors.lastname: Salvesen
authors.forename: Anne K
authors.initials: AK
authors.lastname: Daltveit
authors.forename: Johan F
authors.initials: JF
authors.lastname: Skomsvoll
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000150:complications*; D001722:Birth Order; D002585:Cesarean Section / Q000706:statistics & numerical data*; D000013:Congenital Abnormalities / Q000453:epidemiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008297:Male; D008423:Maternal Age; D009664:Norway; D016017:Odds Ratio; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology; D047928:Premature Birth / Q000453:epidemiology; D012042:Registries; D014592:Uterine Hemorrhage / Q000453:epidemiology
keywords: Birth registry; first birth; pregnancy outcomes; rheumatoid arthritis; subsequent births