ObjectiveMultiple guidelines recommend continuing hydroxychloroquine (HCQ) for SLE during pregnancy based on observational data. The goal of this individual patient data meta-analysis was to identify the potential benefits and harms of HCQ use within lupus pregnancies.MethodsEligible studies included prospectively collected pregnancies in women with lupus. After a systematic literature search, seven datasets meeting inclusion criteria were obtained. Pregnancy outcomes and lupus activity were compared for pregnancies with a visit in the first trimester in women who did or did not take HCQ throughout pregnancy. Birth defects were not systematically collected. This analysis was conducted in each dataset, and results were aggregated to provide a pooled OR.ResultsSeven cohorts provided 938 pregnancies in 804 women. After selecting one pregnancy per patient with a first trimester visit, 668 pregnancies were included; 63% took HCQ throughout pregnancy. Compared with pregnancies without HCQ, those with HCQ had lower odds of highly active lupus, but did not have different odds of fetal loss, preterm delivery or pre-eclampsia. Among women with low lupus activity, HCQ reduced the odds of preterm delivery.ConclusionsThis large study of prospectively-collected lupus pregnancies demonstrates a decrease in lupus activity among woman who continue HCQ through pregnancy and no harm to pregnancy outcomes. Like all studies of HCQ in lupus pregnancy, this study is confounded by indication and non-adherence. As this study confirms the safety of HCQ and diminished SLE activity with use, it is consistent with current recommendations to continue HCQ throughout pregnancy.