Hydroxychloroquine Levels in Women with Systemic Lupus Erythematosus Associated with Flare Activity but Not with Adverse Pregnancy Outcomes

A new study examined hydroxychloroquine (HCQ, known commercially as Plaquenil®) levels in the blood of women with systemic lupus erythematosus (SLE) in their first trimester of pregnancy. Researchers associated low levels of HCQ with severe maternal flare activity during pregnancy. Blood levels did not predict adverse outcomes for the mother or fetus. HCQ is safe and widely used for more favorable outcomes in people with active disease, including during pregnancy. 

The blood of 174 women in their first trimester was analyzed. Adverse pregnancy outcomes (fetal/neonatal death, placental insufficiency with preterm delivery, small-for-gestational-age neonates) occurred in 28 women (16.1%) and were not significantly different by HCQ level in study participants. 

However, researchers found women with subtherapeutic (drug level lower than usually prescribed) and non-adherent (not taking medication as directed) levels of HCQ (≤500 ng/mL and ≤200 ng/mL, respectively) exhibited significantly more severe flares. 

Women with lupus can have healthy pregnancies. This study supports HCQ blood level assessment in pregnant women to predict severe maternal disease activity in pregnancy. Learn more about lupus and pregnancy.

Read the study