(C-172) Effects of Biological Medication Exposure in Pregnancy and Neonatal Outcomes in Women with Autoimmune Diseases

Background: Autoimmunity issues may negatively affect pregnancy and increase maternal-neonatal adverse outcomes, such as preterm birth, and neonatal death. It is estimated that up to 50% of women with autoimmune diseases require treatment throughout pregnancy to control disease activity, posing a challenge as some of the most used traditional disease-modifying agents are known teratogens. In this regard, biological medication has been an alternative to treat pregnant populations with autoimmune conditions; however, the safety and effectiveness of these drugs are still understudied, mainly in low-middle-income countries. As pregnant women are usually excluded from clinical trials, the identification of teratogenic adverse effects is dependent on pharmacovigilance studies.

Objectives: To evaluate the effect of biological medication during pregnancy and neonatal outcomes in women with autoimmune diseases.

Methods: A population-based retrospective cohort study will be performed among live births of pregnant women aged ≥18 to ≤49 years with autoimmune disease (rheumatoid arthritis, psoriasis, inflammatory bowel disease, etc.) in Brazil. Biological drug records will be linked to the SINASC (Live Birth Information System) live birth cohort to identify the use of biological drugs during pregnancy. Biologic medication exposure will be defined as at least one prescription for a biologic medication (etanercept, infliximab, adalimumab, etc.). The outcomes will preterm birth, small for gestational age, low birth weight (LBW) and Congenital anomalies. The groups will define as biologic exposure (including combination with other therapy) compared with women were not on biologics.

Results: Secular trends, patterns of biological use, and safety of biological discontinuation before and during pregnancy will be examined. The effects of biological exposure on child outcomes will be estimated using several approaches to reduce bias and deal with confounders, including a combination of propensity score-based methods and weighted logistic regressions. Directed Acyclic Graphs (DAGs) will be constructed, including the a priori defined set of confounders and mediators.

Conclusions: The results from this study will advance our understanding of the relationship between biological medication during pregnancy and neonatal outcomes, with widespread implications enabling targeting of critical points along the path from in utero exposure to outcomes to avoid or
mitigate illness and disability over the life course.