ABS0418 LOW INCIDENCE OF NEONATAL INFECTION WITH TNF AND NON-TNF BIOLOGIC DMARD USE IN THE SECOND AND THIRD TRIMESTERS OF PREGNANCY

<h2>Abstract</h2><h3>Background:</h3> Biological disease-modifying antirheumatic drugs (DMARDs) are often required and commonly prescribed in the treatment of rheumatologic diseases. Most biological DMARDs are monoclonal IgG1 antibodies containing an Fc region that allows transfer across the placenta during pregnancy in the second and third trimesters. This has raised concerns over the years regarding newborn immunosuppression and increased risk of infection in the first months of life as there have been reports of neonatal infection with biologic use in late pregnancy. Clinical practice has therefore been governed by a conservative approach to continuing biologics in pregnancy, with safety concerns that often lead to a withdrawal of these drugs. The EULAR pregnancy recommendations from 2016 suggest that infliximab and adalimumab be stopped at 20 weeks and etanercept at 30-32 weeks of pregnancy. Further, the ACR 2020 guidelines for management of reproductive health in rheumatic disease suggest discontinuation of infliximab, etanercept, adalimumab and golimumab in the third trimester of pregnancy and complete discontinuation of anakinra and secukinumab, among other drugs, during pregnancy. Early discontinuation of biologics during pregnancy may cause a disease flare-up in high-risk patients and subsequent worsening of materno-fetal and obstetrical outcomes. Additionally, discontinuation of a biologic and restarting it at a later date may result in antibody formation to the drug, preventing the ability to recapture clinical efficacy. Recently, there has been growing evidence supporting the continuation of biologic DMARDs in pregnancy, with the 2024 Update To The EULAR Points To Consider For Use of Antirheumatic Drugs In Reproduction, Pregnancy And Lactation leaning towards a permissive approach due to a more favourable risk-benefit profile. However, biologic use in late pregnancy remains an understudied area, with limited data available in human subjects. <h3>Objectives:</h3> This study aims to add to the body of research surrounding the use of biologic DMARDs in late pregnancy. Here, we investigate the incidence of infection from birth to 6 months in mothers exposed to biologics in the second and third trimesters of pregnancy. <h3>Methods:</h3> This was a single-center prospective observational study conducted at the Ancaster Rheumatology Clinic, Hamilton, Ontario, Canada. The inclusion criteria included all women with known maternal and neonatal outcomes who were treated with biologics in the second and third trimesters. The incidence of infection was recorded based on hospital records and family reports up to 6 months after birth. <h3>Results:</h3> A total of 75 pregnancies in 59 mothers with biologic exposure in the second and third trimesters were reviewed between 2011 and 2024. Most patients had their last biologic injection in the third trimester of pregnancy, i.e. between 29-40 weeks gestation. 33 patients had rheumatoid arthritis, including 2 with JIA. 19 patients had ankylosing spondylitis, one of which also had IBD and psoriasis. 13 patients had psoriatic arthritis (4 of which also had spondylitis), 3 patients had Behcet's, 5 patients had Crohn's disease (2 of which also had PsA), and 4 had other diagnoses. Patients were treated with the following biologics in pregnancy: 27 were on certolizumab, 17 were on adalimumab, 13 were on etanercept (including one in combination with risankizumab), 9 were on infliximab, 3 were on secukinumab, 3 were on golimumab, 2 were on rituximab and 1 was on anakinra. The mean maternal age at delivery was 32 years (SD 4.3). The mean birth weight was 3140g (SD 651), including 2 twin pregnancies and one fetal demise. In the 75 patients with reported infant outcomes, only 3 infants developed infections between birth and 6 months after birth. This included 3 pneumonia infections, 2 of which were RSV. The mothers of these newborns were on certolizumab and adalimumab. <h3>Conclusion:</h3> In this single center study, the late exposure to biologics in pregnancy yielded a very low incidence of infection in newborns to mothers with autoimmune conditions. The results of this study support the most recent 2024 EULAR Update in taking a more permissive approach to the continuation of biologics in pregnancy for the treatment of autoimmune diseases. <h3>REFERENCES:</h3> <b>Available upon request</b>. <h3>Acknowledgements:</h3> <b>NIL</b>. <h3>Disclosure of Interests:</h3> <b>None declared</b>. © The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.