Auto-immune complete heart block (CHB) is a well-defined consequence of antenatal exposure to maternal anti-SSA/Ro and/or anti-SSB/La antibodies. After birth, the persistence of maternal anti-SSA and/or anti-SSB antibodies passively transferred to the foetus can cause skin rash, vascular, hepatic or neurologic manifestations. Pulmonary involvement is infrequent in a such condition in neonates while pulmonary hypertension (PH) is a common complication of systemic lupus erythematosus (SLE) in adulthood. We report a series of 4 neonates referred to our institution for prenatal diagnosis of auto-immune CHB who developed pulmonary hypertension after birth. Two patients were paced at the time of PH diagnosis and 2 patients weren’t. PH was suspected by transthoracic echocardiography after a PH-free interval ranging from 10 days to 3 months. PH was confirmed by right heart cath (RHC) in all, all had a lung CT-pulmonary angiography and one patient had a pulmonary biopsy at the time of pacemaker implantation. At the RHC all the patients presented a pre-capillary PH (PAPm >25mmHg, PWAP<15mmHg). All our patients presented a vasoreactivity at the O2/NO test performed during the RHC. Lung CT showed ground glass opacities in all patients. The one biopsy showed medial hypertrophy without intimal proliferation. Clinical, hemodynamical, CT scan and even pulmonary biopsy findings were consistent with a lung disease cause for PH. Based on the adult management of PH in SLE patients, immunosuppression therapy with intravenous immunoglobulin and with corticosteroids has been proposed to all but one patient. In 2 cases, it has been necessary to add a treatment with pulmonary vasodilator. By 6 months PH normalized in all patients. This series demonstrated the potential pulmonary involvement in neonatal lupus. The prognostic of PH associated with auto-immune CHB in paediatrics patients seams good if adequately diagnosed and treated.Le texte complet de cet article est disponible en PDF.