To assess the reproductive fitness of mothers of children with juvenile idiopathic arthritis (JIA).
A mail survey assessing pregnancy outcome was carried out among mothers of children with JIA (JIA mothers) treated at a tertiary paediatric rheumatology centre. The best friends of the JIA mothers served as controls. Besides family history, sociodemographics and reproductive outcomes were measured, including the number of pregnancies, pregnancy complications and gestational age at the time of delivery.
JIA mothers (n = 227) and controls (n = 235) had similar sociodemographics and racial backgrounds. On average, JIA mothers reported a greater number of conceptions than controls (3.5 vs 3.1; P = 0.01) but had significantly higher rates of pregnancy complications (25% vs 15%; P<0.001). Corrected for differences in the absolute number of pregnancies between groups, the chances of having a miscarriage [mean (s.d.), 0.12 (0.18) vs 0.09 (0.16); P = 0.02] or preterm delivery [0.08 (0.21) vs 0.04 (0.15); P<0.02] were significantly greater among JIA mothers than controls.
Mothers of children with JIA have impaired reproductive fitness. This phenomenon is unlikely to be the result of difficulty with conception but rather to be due to higher rates of pregnancy loss and premature delivery.