Prenatal exposure to antimalarials decreases the risk of cardiac but not non-cardiac neonatal lupus: a single-centre cohort study.

Objective: Recent studies have suggested that prenatal exposure to HCQ reduces the risk of cardiac neonatal lupus. The aim of this study is to assess if maternal intake of antimalarials (AMs) throughout pregnancy lowered the risk of cardiac and non-cardiac neonatal lupus.

Methods: Consecutive children seen between 1 January 1984 to 1 October 2013 born to women with a CTD and positive anti-Ro and/or anti-La antibodies were eligible for this single-centre retrospective cohort study. A total of 315 individuals were screened and 268 participants were included. Exposure to AMs was defined as HCQ or chloroquine throughout pregnancy. Outcomes were cardiac and non-cardiac neonatal lupus. Frequentist and Bayesian analyses were performed. We hypothesized that prenatal AM exposure would decrease the risk of cardiac but not non-cardiac neonatal lupus.

Results: A total of 268 pregnancies were included; 73 were exposed to AMs throughout pregnancy. Ninety-nine children developed neonatal lupus, 117 remained unaffected and 52 children did not develop cardiac neonatal lupus but could not be categorized as unaffected since their full non-cardiac neonatal lupus status was unknown. Logistic regression suggested a protective effect of AM on cardiac neonatal lupus, but results were not statistically significant [odds ratio (OR) 0.21; P = 0.07]. Bayesian analysis showed that the probability of obtaining a protective effect (OR < 1.0) for cardiac neonatal lupus was significant (98.7%). The effect of AMs on non-cardiac neonatal lupus was not significant (OR 0.78; P = 0.21).

Conclusion: In this large single-centre cohort study, exposure to AMs throughout pregnancy was associated with a decreased probability of developing cardiac but not non-cardiac neonatal lupus.