Researchers have uncovered prepregnancy gene expression signatures that may be associated with improved or worsened rheumatoid arthritis during pregnancy, according to a recent study published by Wright et al in Arthritis Research & Therapy. Researchers collected blood samples from 19 female patients with rheumatoid arthritis and 13 healthy controls and assessed their Clinical Disease Activity Index. They then used RNA sequencing and differential gene expression analysis to examine the patients’ prepregnancy gene co-expression networks and identify the factors that may contribute to improved or worsened disease during pregnancy. The researchers found that 73.7% (n = 14) of the patients experienced improvements in their rheumatoid arthritis symptoms during pregnancy and 26.3% (n = 5) of them experienced worsening of their disease during pregnancy. Although the patients in both groups had a similar Clinical Disease Activity Index at baseline, the researchers observed one co-expression module related to B-cell function that was potentially associated with worsening disease severity during pregnancy and was enriched in genes differentially expressed between the groups. Additionally, the patients in the improved rheumatoid arthritis group demonstrated a neutrophil-related expression signature prior to pregnancy. The researchers hope that their findings can serve as biomarkers to predict whether pregnant patients will experience improved or worsening rheumatoid arthritis, which can in turn provide guidance for personalized treatment.