Researchers reported online in Arthritis and Rheumatology that Children whose mothers have rheumatoid arthritis (RA) are at risk for being born preterm.
It is well documented that maternal rheumatic diseases overall have been associated with adverse outcomes in pregnancy however far less is known specifically about RA and very little is known about the effects of preclinical RA, where there is an absence of overt clinical manifestations.
In order to evaluate the risk of RA on pregnancy researchers from Denmark obtained data from Denmark’s Medical Birth Registry and from the Danish National Hospital Registry for diagnoses of RA between 1977 and 2008.
Among almost 2 million births during the study period, 2,101 of the children were considered exposed to maternal RA, 11,455 were exposed to preclinical maternal RA, and 1,086 were exposed to paternal RA.
The risk of birth before 37 weeks of gestation was determined to be 1.5 times higher for babies whose mothers had been diagnosed with RA. In contrast, exposure to paternal RA was not associated with preterm birth. Children exposed to maternal RA were also found to have a slightly lower fetal size at birth compared to unexposed children.
Despite the finding of heightened risk of preterm birth, the authors reported that the overall effect on birth size was modest. “For women with RA, it is reassuring that only a small reduction in fetal growth was found for most of their children, which will have little, if any, impact on perinatal conditions for the child. Whether it has long-term health consequences for children of mothers with RA is unknown and needs to be studied,” they concluded.