Safety and effectiveness of bDMARDs during pregnancy in patients with rheumatic diseases: Real-world data from the BIOBADASER registry.

INTRODUCTION: Inflammatory rheumatic diseases usually affect women of childbearing age treated with biologic drugs. However, there is a lack of literature on the efficacy and toxicity of biologic disease-modifying drugs during pregnancy. The aim of this study was to determine the presence of pregnant patients treated with bDMARDs in a real-world dataset and to examine the impact of pregnancy and lactation on the evolution of rheumatic disease in a registry of Spanish patients.

METHOD: This was a multicentre prospective study with a real-world setting. Information was obtained from BIOBADASER registry. Patients included are women who got pregnant until November 2020 from 19 rheumatology units. We conducted proportions, means, and standard deviations (SD) to describe the study population and the use of treatments. T-test and Chi-square test were applied to assess differences between groups.

RESULT: Ninety cases of pregnancy were registered (n=68 full-term pregnancies; n=22 spontaneous miscarriages). Most of the cases discontinued bDMARDs during pregnancy (78.9%) but 13 cases continued treatment during pregnancy, mainly using certolizumab pegol. These cases were obtaining better management of rheumatic disease, although the differences were not statistically significant [DAS28-CRP, 2.9 (SD: 1.6) vs. 2.0 (1.2), p=.255; DAS28-ESR, 2.2 (1.0) vs. 1.7 (.5), p=.266]. No serious adverse events were reported during pregnancy and lactation.

CONCLUSION: Being pregnant is still an uncommon condition in patients with rheumatic diseases and using bDMARDs. Our results show that rheumatic disease tended to progress better during pregnancy in patients who continued to take bDMARDs.