The presence of RA in the mother during pregnancy (i.e. maternal RA) has been associated with adverse birth outcomes in several research studies.

A study of 1.9 million births in Denmark showed that maternal RA was significantly associated with low birth weight, as well as with reduced measures of fetal growth such as abdominal circumference and placenta weight, all of which are indicators of long-term health of the child.
Rom AL, Wu C, Olsen J, Kjaergaard H, Jawaheer D, Hetland ML, Vestergaard M, Mørch LS. Fetal growth and preterm birth in children exposed to maternal or paternal rheumatoid arthritis: A nationwide cohort study.
Arthritis Rheumatol. 2014 Dec; 66(12):3265-73.

The presence of RA in the mother (during pregnancy) also appears to affect the long-term health of the children born. Based on data from the above study, children born from mothers with RA had significantly higher morbidity compared to children born from healthy mothers.
Rom AL, Wu C, Olsen J, Jawaheer D, Hetland ML, Ottesen B, Mørch LS. Parental rheumatoid arthritis and long-term child morbidity: a nationwide cohort study.
Ann Rheum Dis. 2015 Dec 23. pii: annrheumdis-2015-208072.

However, it is not known why and how the presence of RA leads to these outcomes in the child. Additionally, it is unclear whether these adverse birth outcomes are the result of exposure of the fetus to a “disease (RA) environment” or to RA medications taken by the mother before and/or during pregnancy.

Our research will provide novel insight into whether the expression levels of different genes in the mother during pregnancy - in response to RA and/or to RA medications - influence the health of the children born from those pregnancies.