To examine the overall cognitive development of children exposed to maternal rheumatoid arthritis (RA) in utero by comparing their school test scores to those of their peers.
Children born in Denmark during 1995-2008 and listed in the National School Test Register were included (n = 738,862). Children exposed to maternal RA were identified through linkage of national registers. In separate analyses, exposure was subdivided according to maternal serostatus. Preclinical maternal RA was included as a separate exposure. The Danish national school tests are mandatory standardized tests. Results from all reading tests (grades 2, 4, 6, and 8) and mathematics tests (grades 3 and 6) from 2010-2017 were included. Test scores were compared according to maternal RA exposure for each test separately using linear regressions.
We identified 934 children exposed to maternal RA in utero. There were no differences in reading test scores between maternal RA exposed and unexposed children. RA exposed children scored poorer in both mathematics tests (adjusted differences of mean score -0.14 SD (95% confidence interval [95% CI] -0.23, -0.06) and -0.16 SD (95% CI -0.26, -0.07). There was no appreciable difference between children by maternal RA serostatus. Children exposed to preclinical RA (n = 589) showed the same pattern of performance as children exposed to RA.
RA-exposed children scored slightly poorer in mathematics tests but performed as well as their unexposed peers in the reading tests. The results do not suggest that RA in pregnancy has a major impact on offspring school performance.