Rheumatoid arthritis can’t be cured, but it can significantly improve naturally during pregnancy in 50%-75% of women, prior research has established. It may worsen or stay the same during pregnancy in others.
As of yet, there’s no way to tell which experience a woman with RA will have. RA occurs in 1% of adults globally and is three times more likely to occur in women.
However, a novel study of 19 women with RA suggests that blood biomarkers before pregnancy may predict who will get better or worse during pregnancy. If confirmed with larger studies, the discovery could lead to personalizing medication choices for women with RA who are seeking to become pregnant and change prepregnancy counseling for physicians.
Findings from the research, conducted by first author Matthew Wright, MS, of Children’s Hospital Oakland (Calif.) Research Institute and colleagues were published online in Arthritis Research & Therapy.
A risky choice for women
Currently, the choice is difficult because stopping medications during pregnancy could cause disease flare and continuing could risk possible harm to the baby as some of the medications have toxic side effects.
Dr. Damini Jawaheer
This is the first study to analyze genetic differences in women with RA who plan to get pregnant, senior author Damini Jawaheer, PhD, research associate professor of medicine in rheumatology at Northwestern University, Chicago, said in an interview.
Identifying women who have the disease and confirming they were planning to get pregnant has been extremely difficult, she noted, especially since the start of their research predated electronic health records (EHRs).
The researchers were able to develop a cohort from work they were already doing with researchers in Denmark, which has a national registry that included both women with RA and women of reproductive age. From there they could contact women about their pregnancy intentions and build the cohort for this study.
Healthy women and women with RA of Danish descent who planned to get pregnant were enrolled and were prospectively followed.
Genetic differences at prepregnancy baseline
Researchers analyzed genetic differences through RNA sequencing before pregnancy from 19 women with RA and 13 healthy women.
Of the 19 women with RA, disease activity improved during pregnancy in 14 and worsened in 5.
Before pregnancy, the researchers found, several neutrophil-related genes were significantly overexpressed in women whose RA later improved during pregnancy. Genes related to B cells were highly expressed among women who worsened. Those elevated B-cell–related gene levels were not seen in the group who improved during pregnancy, Dr. Jawaheer added.
“We don’t understand at this point why that is,” she said.
They also compared the blood samples with women in the control group who did not have RA.
“Comparisons to healthy women revealed that the B-cell signature was specific” to women with worsened RA, the authors wrote. “Thus, at the prepregnancy stage, the two groups of RA women differed significantly from each other in terms of B-cell function.”