Factors associated with time to pregnancy in women with axial spondyloarthritis: A registry‐based multicenter study

OBJECTIVE: To study time to pregnancy (TTP) and factors associated with TTP in women with axial spondyloarthritis (axSpA), compared to women with rheumatoid arthritis (RA). METHODS: We included 274 women with axSpA and 317 women with RA from the Norwegian nationwide registry RevNatus. For all the women, we had retrospectively collected data on TTP, and a subgroup also had prospectively collected data. We compared TTP in women with axSpA to women with RA using Kaplan-Meier plots and log-rank test. To identify factors associated with TTP, we used Cox proportional hazard regression. RESULTS: TTP exceeded 12 months in 21% of women with axSpA. In the subgroup followed prospectively, 32% had TTP which exceeded 12 months. Longer TTP was associated with older age, nulliparity, and longer disease duration, with hazard ratios of 0.97 (95% CI 0.94 to 1.00), 0.66 (95% CI 0.50 to 0.88), and 0.94 (95% CI 0.91 to 0.98) respectively. Disease activity, medication, and self-reported health-related quality of life were not associated with TTP. We found no statistically significant differences between axSpA and RA in regard to TTP. CONCLUSION: In women with axSpA, longer TTP was associated with older age, nulliparity, and longer disease duration.