Hydroxychloroquine use and adverse events in Lupus pregnancy: A Stanford Experience

Background: Relatively recently, women with lupus would be advised against pregnancy. However, with improved diagnosis and management, complicated SLE and history of any organ involvement is not a strict contraindication for future pregnancy. As the literature providing evidence for the safety of hydroxychloroquine (HCQ) use during pregnancy in women with lupus grows, it has become increasingly important to evaluate the changes this intervention has introduced in regard to adverse events in pregnancy.
Aim: To evaluate the association between HCQ use and preterm birth (PTB) and preeclampsia (PE) in pregnant women with lupus.
Methods: A retrospective cohort of 129 pregnancies from 110 women with lupus was formed from 2000-2017 from a single center, Stanford Healthcare. Lupus diagnosis was evaluated and confirmed via medical record review. Data were collected regarding demographics, lupus disease, current pregnancy, delivery, and reproductive history characteristics. HCQ exposure was determined by care plan, physician notes, and prescriptions. Use of low dose aspirin (ASA), a secondary exposure, was also collected during chart review. Logistic regression was used to estimate odds ratios and 95% confidence intervals adjusting for potential confounders.
Results: Due to the limited sample size, statistical analyses were underpowered. However, the association between HCQ use during pregnancy and preeclampsia and preterm birth appeared protective in unadjusted and adjusted analyses accounting for maternal age and race, renal involvement, and antiphospholipid antibody positivity and syndrome (crude OR for HCQ-PTB=0.6, 95% CI=0.3-1.4 crude OR for HCQ-PE=0.4, 95% CI=0.2-1.1). Observed effects were not consistent in ASA analyses, for example the crude OR for ASA-PTB was 1.5, 95% CI (0.6-4.1) and the crude OR for ASA-PE was 0.6 95% CI (0.2-2.1).
Conclusion: While our study does suggest protective effects with HCQ use during pregnancy against preeclampsia and preterm birth in women with lupus, our sample size limitations hindered our ability to fully investigate potential effect modification by parity. Additional research is required to achieve sufficient power to adequately investigate effect modification by factors such as antiphospholipid antibodies (aPL) and antiphospholipid syndrome (APS).