Parity in patients with chronic inflammatory arthritides childless at time of diagnosis

Objective: To assess parity in women with chronic inflammatory arthritides (CIA) childless at time of diagnosis. Methods: Patients were selected from the Norwegian Disease-Modifying Anti-Rheumatic Drug (NOR-DMARD) registry. Each patient was matched by year of birth with 100 reference women from the Norwegian Population Registry. Data linkage for patients and references with the Medical Birth Registry of Norway (MBRN) identified all offspring until time of linkage (October 2007). Patients and corresponding references childless at the time of diagnosis were included in the analyses. Kaplan-Meier curves visualized the proportion of childless women and were compared by a log rank test. Results: In all, 156 rheumatoid arthritis (RA), 107 other chronic arthritides (OCA), and 75 juvenile idiopathic arthritis (JIA) patients were childless at time of diagnosis. At the time of data linkage, the proportions (%) of childless RA/OCA/JIA patients versus references were 61.5/62.6/57.3 versus 46.9/42.9/41.0, respectively, all differences statistically significant. The log rank test showed lower parity in all diagnostic groups compared with references (p < 0.001 for RA and OCA and p = 0.002 for JIA). No difference in parity was observed between RA and OCA patients, but both diagnostic groups had lower parity than JIA patients (p = 0.001). Disease characteristics were similar between childless and fertile patients. Conclusions: Reduced parity was observed in all diagnostic groups compared with references. RA and OCA patients had lower parity than JIA patients, indicating that having the disease as a young adult may influence parity more than having the disease in childhood.