A RECENT population-based cohort study has provided reassuring news for pregnant women with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) who require treatment with hydroxychloroquine (HCQ). The study, which assessed the risk of major congenital malformations (MCM) associated with first-trimester exposure to HCQ, found no significant increase in the risk of MCM among infants born to mothers treated with the drug.
Researchers utilised data from the Swedish nationwide registers to examine all singleton births between 2006 and 2021 to mothers with prevalent SLE or RA. The study included 1007 births in the SLE cohort, of which 453 were exposed to HCQ, and 2500 births in the RA cohort, with 144 exposed to HCQ. The primary outcome was the incidence of MCM within the first year of birth.
To account for potential confounders such as maternal smoking, body mass index, pregestational diabetes, and corticosteroid use, the study applied inverse probability of treatment weighting. The risk ratios (RR) for MCM were estimated using modified Poisson regression models with robust variance.
Results showed that in the SLE cohort, the overall risk of MCM was 3.6%, with 3.7% in the exposed group and 3.4% in the unexposed group. The adjusted RR was 1.29 (95% CI 0.65–2.56). And in the RA cohort, the overall risk of MCM was 4.4%, with 5.6% in the exposed group and 4.3% in the unexposed group. The adjusted RR was 1.32 (95% CI 0.56–3.13). The adjusted RR for the pooled SLE and RA cohorts was 1.30 (95% CI 0.76–2.23).
The study also found that the adjusted risk difference between exposed and unexposed groups was small, at 0.9% for SLE and 1.3% for RA.
The study concluded that first-trimester exposure to HCQ is not associated with a significantly increased risk of major congenital malformations. These findings suggest that the benefits of HCQ in managing SLE or RA during pregnancy likely outweigh the potential risks, supporting the continued use of HCQ for pregnant women with these conditions.
This study provides essential evidence for healthcare providers managing pregnant women with SLE or RA, affirming the safety of HCQ during the first trimester. It emphasises the importance of balancing the need for effective disease management with potential risks to foetal health, which ultimately supports the therapeutic use of HCQ in pregnancy.
Further research may focus on long-term outcomes for children exposed to HCQ in utero and explore additional factors that could influence maternal and foetal health in women with autoimmune diseases.
Aleksandra Zurowska, EMJ
Reference:
Nguyen N V et al. Hydroxychloroquine in lupus or rheumatoid arthritis pregnancy and risk of major congenital malformations: a population-based cohort study. Rheumatology. 2024:keae168.
