OA09 Foetal Complete Heart Block in Ro positive Sjögren’s Syndrome patients- do we need a new prevention paradigm?

Abstract Introduction Sjögren’s Syndrome (SS) remains under recognised and frequently under treated. It affects approximately 0.6% of adults in the UK, with a mean age of 50 years. It is more common in women and young adults and thus pregnancy is not uncommon in affected women resulting in an increased impact of the disease on pregnancies. There is an increased rate of pregnancy complications including spontaneous abortion, foetal loss, congenital heart block (CHB) and neonatal lupus. We present a case series of three pregnant patients with foetal congenital heart block, with varying outcomes, highlighting gaps in current knowledge and medical practice. Case description Case 1: A female, born in 1986, suffering with dry eyes/mouth, was diagnosed with SS in 2018. Ro and La antibodies were intermittently positive during disease flare- mainly rash secondary to hypergammaglobulinemia. Mother had SS. In October 2022, an echo during the first pregnancy, at gestational age of 20 weeks+4 days with expected date of delivery (EDD) in March 2023, showed CHB with atrial and ventricular rate of 147 and 57 bpm respectively and no hydrops. Hydroxychloroquine (HCQ) 400 mg od and Dexamethasone 4 mg od were started. She underwent weekly echo. At the end of October 2022, ventricular rate dropped to 50 bpm. Salbutamol was started. She underwent a caesarean-section (CS), a month before EDD and baby received temporary pacemaker, 2 days post CS. Case 2: A female, born in 1997, had a history of intermittent joint pain, no sicca symptoms and Ro/La antibodies were positive. Mother had two miscarriages. In 2018, G1P1, she had CS at 36 weeks. Baby died soon after delivery due to CHB. In her second pregnancy in 2019, she underwent CS at 33 weeks and delivered a healthy baby with no complications. During third pregnancy in 2020, foetus developed congenital heart block from 16 weeks onwards. She delivered baby, via CS, two months before EDD. Baby died four months later due to multiple organ failure. In 2022, she delivered a full-term heathy baby, via CS. Foetus had CHB at 20 weeks, but it disappeared within a week. Case 3: A female, born in 1988, G2P1 with a healthy child, had an echo in Jan 2023 at 18 weeks of pregnancy. Echo showed CHB with pericardial effusion, atrial and ventricular rate of 103 and 47 bpm respectively. Dexamethasone and salbutamol were started. At 24 weeks, foetal hydrops was present with no heart sounds. Discussion All three patients had high Ro/La antibodies: Ro >