Hydroxychloroquine does little to prevent pre-eclampsia in pregnant women with lupus

The use of hydroxychloroquine during pregnancy does not appear to reduce the risk of pre-eclampsia among women with systemic lupus erythematosus (SLE), as shown in a study.

For the study, researchers looked at 1,068 livebirth singleton pregnancies among 1,020 privately insured patients with SLE. Hydroxychloroquine use was defined as 3 months preconception through the first trimester, with prescription fills used as a proxy for use. Modified Poisson regression was used in the analysis.

Pre-eclampsia occurred in 15 percent of pregnancies, and at least one hydroxychloroquine fill was documented in 52 percent of pregnancies.

Compared with unexposed pregnancies, those that were exposed to hydroxychloroquine had more comorbidities, SLE activity, and azathioprine use. Hydroxychloroquine use showed no protective effect against pre-eclampsia among nulliparous (risk ratio [RR], 1.26, 95 percent confidence interval [CI], 0.82–1.93) and multiparous pregnancies (RR, 1.20, 95 percent CI, 0.80­–1.70).

In further analysis wherein propensity scores were applied to account for confounding, the estimates were attenuated (nulliparous: adjusted RR, 1.09, 95 percent CI, 0.68–1.76; multiparous: adjusted RR, 1.01, 95 percent CI, 0.66–1.53).

The analysis was based on a large insurance database. However, the investigators acknowledged potential limitations such as residual and unmeasured confounding and misclassification. Additional research harnessing large population-based data and prospective studies are needed to establish the effect of hydroxychloroquine on the risk of pre-eclampsia in pregnant women with SLE and in those at increased risk of hypertensive disorders of pregnancy.