Systemic hypertension in very low-birth weight infants with bronchopulmonary dysplasia: incidence and risk factors.

The purpose of our study was to determine if systemic hypertension (HTN) occurred among infants with birth weight less than 1250 g (very low-birth-weight [VLBW] infants) in association with Bronchopulmonary dysplasia (BPD). We designed a historical cohort study to review the clinical course and the occurrence of systemic HTN in infants born during the year 1992 with birth weights between 600-1250 g. The overall incidence of HTN was 6.8% (5 of 73) and the incidence in infants with BPD was 12% (5 of 41). The mean age of onset of HTN was 105 days (range 90 to 133 days), and at the time of discharge 3 of 5 (60%) infants remained hypertensive and 3 of 5 (60%) were on supplemental oxygen. All the five hypertension infants (100%) were on supplemental oxygen at 36 weeks of postceptional age compared to 18 of 36 (50%) of nonhypertensive BPD infants. The association between HTN and severe BPD was further denoted by longer hospital stay (145 +/- 37 vs. 94 +/- 28 days, p = 0.004), longer duration of O2 therapy (108 +/- 36 vs. 67 +/- 34 days, p = 0.01), and prolonged use of aminophylline (104 +/- 44 vs. 61 +/- 23 days, p = 0.03), in the hypertensive BPD infants versus nonhypertensive BPD infants, respectively. This study substantiates an increased risk of developing systemic HTN, among VLBW infants with severe BPD.