LATEBREAKER
Perinatal & Pediatric
Fetal Growth Associated with Maternal Rheumatoid Arthritis and Juvenile Idiopathic Arthritis. Eugenia Chock* Eugenia Chock Zeyan Liew Lars Henning Pedersen Mette Oestergaard Thunbo
Introduction: Maternal chronic inflammatory arthritis, including rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA), is associated with a higher risk of preterm delivery and infants with low birth weights, but the timing and trajectory of fetal growth during pregnancy associated with these maternal conditions have not been well studied.
Methods: We conducted a population-based cohort study in Denmark from 2008-2018 which included 503,491 singleton pregnancies. Among them, 2,206 mothers have received an RA or JIA diagnosis (RA/JIA) before or during pregnancy. We analyzed 2nd trimester fetal ultrasound measurements (at 18-22 weeks’ gestation) extracted from the Danish Fetal Medicine Database. We first examined the estimated fetal weight (EFW) at the 2nd trimester and the recorded birth weight separately. Then, we calculated the fetal growth gradient by computing the mean difference between the fetal weight and the birth weight Z-scores. We conducted linear regression analyses for these outcomes comparing pregnancies with or without RA/JIA adjusting for confounding factors. We further stratified the maternal RA/JIA groups by the antirheumatic therapies received during pregnancy.
Results: Maternal RA/JIA was not associated with a reduction of EFW in mid-pregnancy, but a lower birth weight (Z- scores mean difference: -0.08; 95%CI -0.13, -0.04). Maternal RA and JIA was associated with fetal growth gradient reduction computed using the 2nd trimester EFW and birth weight measures (Z-score mean difference: -0.14; 95%CI -0.08, -0.19), with the largest growth reduction observed among mothers with RA/JIA who used corticosteroids (-0.26; 95%CI -0.11, -0.41) and sulfasalazine (-0.61; 95%CI -0.45, -0.77) during pregnancy.
Conclusion: Offspring born to individuals with RA/JIA had lower birth weight; with the greatest gradient of fetal growth reduction noted during the late pregnancy period, and among corticosteroid and sulfasalazine users.