HCQS in Early Pregnancy Does Not Reduce Preeclampsia or preterm delivery Risk in SLE: Study

In order to evaluate the effectiveness of hydroxychloroquine as a preventive measure and exclude other variables that could affect the results, scientists undertook a large-scale study on a cohort of the entire population. In this case, the study analyzed the clinical data from the British Columbia Perinatal Data Registry, where there is information about singleton pregnancies in women insured by the public health care system with a diagnosis of systemic lupus erythematosus before conception.

For the definition of exposure windows for the use of active hydroxychloroquine, scientists used several strict windows and demanded that patients receive at least two medications or at least 60 days of treatment in the first 20 weeks of pregnancy. Scientists employed modified Poisson regressions along with propensity scores in order to compare patients without confounding due to the baseline characteristics of maternal covariates (age, parity, etc.). Moreover, a time-to-event analysis of the Cox proportional hazards model was used to determine the dynamics of preterm delivery.

Key findings:

• Cohort study using population-based data was able to monitor and analyze 847 singleton pregnancies in its baseline sample size.
• The registry data that were examined followed pregnancies in a primary cohort of 597 publicly insured patients with pre-existing systemic lupus erythematosus.
• Maternal population had a mean age of 33.1 years with a standard deviation of 4.6 years and consisted of exactly 43% nulliparous women.
• In comparison between pregnancies with at least 2 fills and 60 days of drug supply versus pregnancies without any fills, the adjusted risk ratio was calculated to be 0.92 (95% CI, 0.47 to 1.80).
• Risk ratios of the development of vascular events in case when the period before conception is added were neutral too.
• Time-to-event Cox proportional hazards models showed no significant findings regarding multiple alternatives of the definition of preterm delivery.

In summary, the use of HCQ in early pregnancy in women with SLE has no clear correlation with lower risks of preeclampsia or preterm birth. Larger cohorts will be required to determine these correlations. The highly relevant figures from the regional registry demonstrate a key empirical basis for contemporary obstetric epidemiology, showing that reducing maternal inflammation is insufficient for solving specific placental vascular disorders.

Reference:

Sediqi, S., Lu, N., Avina-Zubieta, A. and Simard, J.F. (2026), Hydroxychloroquine Use, Preeclampsia, and Preterm Delivery Complications in Systemic Lupus Erythematosus Pregnancies: Is There a Protective Effect?. Arthritis Care Res. https://doi.org/10.1002/acr.80046