SIX-YEAR FOLLOWUP OF NEONATAL RENOVASCULAR (NRH) HYPERTENSION

Neonatal hypertension is often associated with renal artery thrombosis after use of umbilical artery catheters. Although infants with NRH usually respond to medical therapy, their prognosis is unclear; longterm followup of 11 infants is presented. Mean birthweight was 2914 gm; pre-treatment blood pressure, 161/100 mmHg, and age of onset, 7.8 days. 9 of 11 infants had umbilical artery catheters. A renal abnormality was noted on renal scan or angiography in 9 of 11 infants. 7 of 10 infants studied had elevated peripheral plasma renin activity (PRA). All infants became normotensive with diuretic and/or antihypertensive agents and remained so when weaned off drugs. 2 infants died at 3 months of age of SIDS and pneumonia. The remaining have been followed for 5.5 to 7.5 years. 2 children, neither small for gestational age, have heights and weights below the 5th percentile for age. One child has a creatinine clearance of 62 ml/min/1.73 m2. PRA in 8 children studied is normal. Renal ultrasound, intravenous pyelography, and renal scan demonstrate persistent renal abnormalities in 7 of 9 children. Neonates with NRH responded well to antihypertensive medication, remained normotensive off medications, but had significant abnormalities in renal size and function which persisted over a 6 year period. Because their ultimate prognosis is unclear, longterm followup of infants with NRH is indicated.