After consulting several studies describing the efficacy of this drug in decreasing the overall risk of cardiac–neonatal lupus, the author suggests a pre-emptive treatment with hydroxychloroquine (400 mg orally once per day) in pregnant women who have previously given birth to a child with cardiac manifestations of neonatal lupus and who have anti-Ro/SSA and/or anti-LA/SSB antibodies, regardless of maternal health status (Grade 2B). This evidence concerns the gene TRIM21 and systemic lupus erythematosus.