Background and aims Neonatal lupus erythematosus (NLE) is a passively acquired autoimmune disease of infancy, caused by the transplacental passage of maternal autoantibodies, mostly anti-RO/SSA and anti-LA/SSB. NLE presents with a transient rash and/or congenital heart block (CHB). The risk of developing NLE in SSA-positive women is ˜2%, however the risk increases to 25%, if the mother has had a previous child with NLE.

Objectives We present a case of NLE characterised by a third-degree CHB, ascites and life-threatening pericardial effusion, which was treated twice with intrauterine pericardiocentesis in week 22 and 29. After birth the child was treated with systemic corticosteroid on and off for 1 year, and she later received a pacemaker and was treated with ACE inhibitor and diuretics due to heart failure. Now, at the age of 6 years, she is still treated with ACE inhibitor. Her older sister also had NLE and her mother was found to have asymptomatic anti-SSA >100 U/ml.

Discussion This case is exceptional, as the fetus had severe exudative pericarditis and had life-saving pericardiocentesis performed in utero. We want to draw the clinicians’ attention to the increased risk of NLE, when a mother earlier has given birth to a child with NLE. Regular fetal echocardiography is important from week 16. In case of first- and second-degree CHB, maternal corticosteroid can be tried to reverse the condition. Also, treatment with hydroxychloroquine or IVIG may decrease the risk of CHB.