New research demonstrates how important it is for women with lupus to continue taking their hydroxychloroquine (HCQ) as prescribed during pregnancy and suggests that higher doses for pregnant women may be warranted. First, the study found that HCQ behaves differently in the body during pregnancy, causing its concentrations in the blood stream to drop more quickly than in non-pregnant users. Additionally, persistently low blood concentrations of HCQ were associated with significantly higher risk of preterm birth.

Researchers followed 56 pregnant women with lupus from their first trimester to their post-partum doctor’s visits and observed how HCQ levels in the bloodstream compared to the levels that would be expected at their given dosages. They found about one in four (25.2%) women had significantly lower-than-expected blood levels of HCQ at some point between their first trimester and post-partum appointment. And, nearly one in five (19.7%) had chronically low HCQ concentrations consistently throughout their pregnancy.

Two-thirds of the women with low average HCQ blood levels had preterm births. Women who delivered their babies early were more likely to have low HCQ concentrations, regardless of race, kidney disease status, and their use of other medications (azathioprine and prednisone). Disease activity was also found to be higher in those with low HCQ concentrations.

A healthy pregnancy is possible for women with lupus, and HCQ (known commercially as Plaquenil®) is safe to continue taking if you become pregnant. Learn more about lupus and pregnancy.

Read the Study