To determine the difference in the risk factors for systemic hypertension in preterm and term infants in the neonatal intensive care unit (NICU).

Data were collected from an existing database of NICU children and confirmed by chart review. Systemic hypertension was defined when 3 separate measurements of systolic and/or diastolic blood pressure were >95th percentile and an antihypertensive medication was administered for >2 weeks in the NICU.

Of 4203 infants, we identified 53 (1.3%) with treated hypertension, of whom 74% were preterm, 11% required surgical intervention, and 85% required medications on discharge. The presence of a patent ductus arteriosus, umbilical catheterization, left ventricular hypertrophy, hypertensive medication at discharge, and mortality was similar between the term and preterm infants. The major risk factors for preterm infants, especially those <28 weeks' gestation, were bronchopulmonary dysplasia and iatrogenic factors, but, in term infants, they were systemic diseases. Term infants were diagnosed with hypertension earlier during hospitalization, had a shorter duration of stay in the NICU, and had a higher incidence of hypertension needing >3 medications than preterm infants.

Perinatal risk factors are significant contributors to infantile hypertension. Term infants were diagnosed with hypertension earlier, had a shorter duration of stay, and had a higher incidence of resistant hypertension than preterm infants.