Pos0560 outcome of neonates born to patients with rheumatic diseases compared to healthy controls

Background In general, more women are affected by rheumatic diseases and often during their reproductive age. Due to disease activity and/or specific autoantibodies autoimmune diseases might lead to impaired fetal outcome. Data from large registries help to improve information on the risks for patients and infants and thus enable us to better advise our patients. Objectives To analyse fetal outcome of babies born to patients with rheumatic diseases by different parameters and compare to healthy controls. Methods This study compares registry data from 2012–2022 from a specialized centre. We included 351 pregnancies from patients with rheumatic diseases and 1298 from age-matched HC. Results Patients with rheumatic diseases were distributed as follows: 58% CTD, 15% RA, 13% SpA, 5% autoinflammatory diseases and 4% vasculitis. Spontaneous abortion rate with 5% was comparable to the general population [1] , APGAR, and umbilical cord pH were comparable to HC. Babies born to patients with rheumatic diseases have a significantly different outcome compared to HC: they present with lower birth weight (3245g vs 3038g; p<0.001) and length (50.7cm vs.49.7cm; p<0.001), higher number of intrauterine growth retardation (IUGR; 3% vs 7%; p<0.05) and are more often preterm (10% vs 16%; p<0.01).There is also a difference in the delivery mode, with a significant higher rate of scheduled caesarean birth rate (12%vs.32%;p<0.001),however not of unplanned caesarean birth. We also observed higher number of congenital anomalies (6%vs.12%;p<0.01) usage of postpartal continuous positive airway pressure (CPAP) therapy (4%vs.12%;p<0.001) and transfer to specialized neonatal care (10%vs.19%;p<0.001).When comparing different groups of rheumatic diseases, our analysis shows mainly abnormalities for CTD (especially SLE, Sjogren’s syndrome and undifferentiated CTD),with high rates of small for gestational age (SGA; SLE:19%, SS:28%; UCTD:28%), high proportion of planned caesarean birth (SLE:44%).However, congenital anomalies were also more prominent in the group of patients with SpA. Interestingly, in the age group >35years patients and HC assimilated, eg we did not observe significant differences for birth weight anymore. Conclusion Fetal outcome of neonates born to patients with rheumatic diseases in general is favourable, as we observed a live birth rate of 95%. This is also supported by important parameters as APGAR and umbilical cord pH, which did not differ in between groups. However, the number of children born before 37gw and lower birth weight/length is significantly higher compared to HC. This has been suggested by us and other groups [2-4] , but we here compare the fetal outcome of patients to an age-matched HC group from the same hospital, and therefore more comparable and valid data. One might speculate, that higher rates of preterm births explain the higher admission rate to neonatal care and CPAP therapy. Our data reveal, however, that these differences mainly affect patients with CTD, especially SLE, SS, UCTD, which is of special interest for the risk assessment in the treatment of pregnant patients with rheumatic diseases. Even though spontaneous abortion rates do not differ to the general population, we observed a significantly higher number of congenital anomalies. Further studies are necessary to determine the underlying cause, as both, disease activity and immunosuppressant medication might be responsible. References [1]Magnus, M.C., Wilcox, A.J., Morken, N.H., Weinberg, C.R. & Haberg, S.E. Role of maternal age and pregnancy history in risk of miscarriage: prospective register based study. BMJ 364 , l869 (2019). [2]Petri, M. Pregnancy and Systemic Lupus Erythematosus. Best Pract Res Clin Obstet Gynaecol 64 , 24-30 (2020). [3]Gayed, M. & Gordon, C. Pregnancy and rheumatic diseases. Rheumatology (Oxford ) 46 , 1634-1640 (2007). [4]Pecher, A.C. , et al. Pregnancy outcome is favorable in patients with rheumatic diseases under specialized surveillance - Data from the Tuebingen registry for pregnancy in rheumatic diseases in 238 pregnancies. Joint Bone Spine 88 , 105073 (2021). Acknowledgements: NIL. Disclosure of Interests Ann-Christin Pecher Speakers bureau: Novartis, UCB, Boehringer Ingelheim, Julia Niessen: None declared, Peter Jakubowski: None declared, Harald Abele: None declared, Jörg Henes Speakers bureau: BI, ABBVIE, Chugai, Pfizer, UCB, Novartis, SOBI, BMS, Consultant of: BI, Novartis, VIFOR, Grant/research support from: Chugai, SOBI, Novartis.