title: Fertility in women with chronic inflammatory arthritides.
abstract: OBJECTIVE
  To compare fertility rates in women with RA, other chronic arthritides (OCAs) and JIA with reference women from the general population.
  
  
  METHODS
  Each woman from a Norwegian patient registry was matched by year of birth with 100 reference women randomly selected from the National Population Registry. Data linkage of patients and references with the Medical Birth Registry of Norway (MBRN) identified all offspring in patients and references until October 2007, and indirectly also nulliparous (childless) women. Groups were compared with Mann-Whitney U-test for continuous variables and chi-squared tests for categorical variables. Poisson regression analysis was applied to calculate relative fertility rates in the diagnostic groups vs references.
  
  
  RESULTS
  Among 631 patients 849 children were registered in MBRN. Of these, 289 children (34.0%) were born after time of diagnosis vs 44.3% in references. Altogether, 206 of 631 patients (32.6%) were nulliparous vs 26.4% in references (P < 0.001). Among RA patients, 28.4% (96 of 338) were nulliparous vs 24.5% in references (P = 0.09), 30.7% (67 of 218) in OCA patients vs 24.5% in references (P = 0.03) and 57.3% (43 of 75) in JIA patients vs 40.9% in references (P = 0.004). Adjusted relative fertility rates in RA, OCA and JIA after diagnosis were 0.88, 0.84 and 0.84, respectively, compared with references.
  
  
  CONCLUSIONS
  A higher proportion of women with chronic inflammatory arthritides were nulliparous compared with references, and relative fertility rates were reduced in all patient groups.
authors.affiliation: Department of Rheumatology, St Olav's Hospital, Trondheim University Hospital, Bevegelsessenteret, N-7006 Trondheim, Norway. marianne.wallenius@ntnu.no
authors.forename: Marianne
authors.initials: M
authors.lastname: Wallenius
authors.forename: Johan F
authors.initials: JF
authors.lastname: Skomsvoll
authors.forename: Lorentz M
authors.initials: LM
authors.lastname: Irgens
authors.forename: Kjell Å
authors.initials: KÅ
authors.lastname: Salvesen
authors.forename: Bjorn-Yngvar
authors.initials: BY
authors.lastname: Nordvåg
authors.forename: Wenche
authors.initials: W
authors.lastname: Koldingsnes
authors.forename: Knut
authors.initials: K
authors.lastname: Mikkelsen
authors.forename: Cecilie
authors.initials: C
authors.lastname: Kaufmann
authors.forename: Tore K
authors.initials: TK
authors.lastname: Kvien
mesh_terms: D000328:Adult; D017677:Age Distribution; D001171:Arthritis, Juvenile / Q000175:diagnosis / Q000453:epidemiology; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000453:epidemiology; D001723:Birth Rate / Q000639:trends*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015994:Incidence; D009664:Norway; D010298:Parity; D016012:Poisson Distribution; D011247:Pregnancy; D018873:Pregnancy Rate / Q000639:trends*; D012016:Reference Values; D012042:Registries; D012216:Rheumatic Diseases / Q000175:diagnosis / Q000453:epidemiology; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D055815:Young Adult