Azathioprine Exposure Associated with Liver Condition in Systemic Lupus Erythematosus Pregnancies

Intrahepatic cholestasis of pregnancy (ICP) is a liver condition that can occur late (after 20 weeks) in pregnancy. A new study found a strong connection between azathioprine (AZA, an immunosuppressive medication commonly used to help manage lupus during pregnancy) exposure and development of ICP in women with systemic lupus erythematosus (SLE). 

Researchers examined 127 SLE pregnancies in the LEGACY cohort across Canada, South Korea, Peru, and Mexico. Of the group, 46 women were exposed to AZA and 81 were not exposed to the drug therapy. The women were monitored in their second (20–24 weeks) and third (30–34 weeks) trimesters and postpartum (8–12 weeks). They observed an over-tenfold increase in ICP risk among AZA-exposed pregnancies. Additionally, all AZA-exposed ICP cases with available metabolite data exhibited thiopurine shunting (a metabolic complication associated with ICP), supporting a potential biological mechanism.

Compared to unexposed SLE pregnancies, the study shows a substantial increased risk of ICP in women exposed to AZA during their pregnancy. Thiopurine shunting in the second trimester may also be a strong predictor of ICP, though larger studies are needed to confirm this finding This research is not meant to discourage AZA use in lupus pregnancies; however, the researchers encourage close monitoring and early attention to any signs of liver issues in pregnant women with SLE to help protect both mother and baby. It’s recommended to talk to your doctor before making any changes to your treatment. Learn more about lupus and the liver.

Read the study