Women with SLE face a high risk of preeclampsia (PE). Therefore, low dose Aspirin (LDA) is recommended for SLE pregnancies to protect against PE. Lately, a beneficial effect of hydroxychloroquine (HCQ) has been discussed. We aimed to investigate the influence of LDA and HCQ on the occurrence of PE in SLE.
SLE pregnancies from an outpatient pregnancy clinic were prospectively evaluated. Association of timely LDA or HCQ use with PE was analysed using a multiple logistic regression model.
We enrolled 190 pregnancies. Additional risk factors for PE were present in 83.7%: high-risk profile (HRP) in 55.8% (history of PE, hypertension, lupus nephritis, aPL), moderate risk factor in 27.9% (nulliparous, BMI>30, age>35). Each 20.5% of pregnancies received HCQ or LDA only, while 22.6% were prescribed both. Women with HRP were more likely to take LDA alone or in combination with HCQ (28.3% and 35.8%, respectively).
PE occurred in 13.2% (7.7% HCQ only, 15.4% LDA only, 14.0% HCQ and LDA, 14.5% no HCQ or LDA). Most pregnancies affected carried a HRP (88.0%).
Use of LDA was significantly associated with a lower risk for PE [aOR 0.21 (95%-CI 0.05-0.99), p<0.05]. HCQ use also had a moderating effect [aOR 0.47 (95%-CI 0.15-1.52), p=0.21]. If only pregnancies with HRP were considered, the effect size increased for HCQ [aOR 0.28 (95%-CI 0.07-1.14), p=0.075].
In this real-life cohort, a favourable effect on the occurrence of PE was partially explained by HCQ. In particular, SLE patients at high risk for PE seem to benefit from HCQ during pregnancy.