Juvenile idiopathic arthritis, marriage and parenthood: a nationwide matched cohort study

To compare trajectories of marriage and parenthood in individuals with JIA vs the general population.

Patients with JIA (n = 4399) were identified in the Swedish National Patient Register (2001-2016) and individually matched to up to five general population comparators on birthyear, sex and residence county (n = 21 981). Marriage and parenthood data were retrieved from the Total Population Register from age 18 y, and parenthood from the Multigeneration Register from age 15 y, respectively. Hazard ratios (HRs) were estimated using Cox regression adjusted for parental education, parental marital status and number of siblings.

During a median of 6.3 years of follow-up, 362 patients with JIA and 1744 comparators got married (12.9 vs. 12.5 per 1000 person-years; HR 1.03, 95%CI 0.93-1.15). During a median of 8.8 years of follow-up, 680 patients with JIA and 3477 matched comparators became parents (17.1 vs 17.8 per 1000 person-years; HR 0.94, 95%CI 0.87-1.01). In the subgroup of patients with systemic onset JIA (SJIA), the adjusted hazard ratios for marriage and parenthood were 0.79 (95%CI 0.53-1.17) and 0.73 (95%CI 0.55-0.97), respectively.

The times to first marriage and first parenthood are similar for patients with JIA and the general population, suggesting that adolescents with JIA transition into family life along a trajectory resembling their community peers. One exception is the subgroup of patients with systemic onset JIA, who become parents for the first time at a lower rate than general population comparators.