Arterial hypertension is rare in the neonate where it has high morbidity and mortality. Renovascular disease is the leading cause of neonatal hypertension. We report a case of severe hypertension in a 34 week gestation male neonate due to 90% right renal artery stenosis. The neonate presented at birth with malignant hypertension, hematuria, proteinuria, and normal GFR. Initial course was complicated by salt wasting, retinal arteriolar narrowing and labile blood pressure. Renal biopsy showed normal fetal architecture with ongoing nephrogenesis. Based on the biopsy findings, antihypertensive therapy with Captopril was temporarily discontinued due to its known adverse affect on the renin angiotensin axis and subsequent renal development. Despite no perfusion to the left kidney on radionuclide studies, renal ultrasound and Doppler flow studies were normal on two occasions. Arteriogram revealed long segment stenosis of the left main renal artery. Left nephrectomy resulted in resolution of hypertension and withdrawal of all medical therapy.

This case demonstrates the presence of congenital renal artery stenosis and secondary hypertension in a neonate. It further raises concern over the use of angiotensin converting enzyme inhibitors in premature neonates with ongoing post-natal nephrogenesis. This case illustrates the lack of sensitivity of Doppler flow studies in detecting renal artery disease. Suspicion of renovascular disease in neonates necessitates thorough radiological evaluation including radionuclide studies and arteriogram.