Early neonatal renal venous thrombosis: long-term outcome.

Renal venous thrombosis was diagnosed in the first week of life in 6 of 30,101 live infant births born at the Chaim Sheba Medical Center in Israel from 1984 to 1989. The thrombosis was unilateral in 5 neonates and bilateral in 1. Predisposing maternal risk factors included 2 cases of maternal diabetes and 1 case of maternal hypertension with associated intrauterine growth retardation. Perinatal risk factors included 2 cases of prematurity with severe hyaline membrane disease, 1 infant who was small for gestational age and another with asphyxia. Follow-up for 1-5 years following the acute event revealed normal growth and development in all infants. None of the patients was hypertensive and all had normal renal glomerular and tubular functions. Renal imaging and scan studies revealed loss of perfusion in 4 atrophic kidneys and diminished perfusion in the remaining 2. In conclusion, although renal venous thrombosis in neonates is associated with low mortality, long-term dysfunction in the affected kidney is common.