Neonatal Hypertension

Hypertension was initially recognized clinically in neonates in the 1970s, but recent technological advances in the NICU have led to heightened awareness and increased diagnostic frequency. Neonatal hypertension is defined as systolic blood pressure (BP) of at least the 95th percentile for gestational age, birthweight, and sex on 3 separate occasions. The incidence of neonatal hypertension in the NICU ranges from 0.2% to 3% and most commonly affects term and preterm infants in the intensive care setting.

Abnormally elevated BP, especially severe (defined by systolic BP >99th percentile) in critically ill or premature infants can result in vascular injury, left ventricular hypertrophy, encephalopathy, and hypertensive retinopathy. In addition to complications from end organ damage, certain forms of neonatal hypertension are linked to hypertension beyond infancy, making it imperative to swiftly diagnose and aggressively manage severe or persistent hypertension.

As with older children and adults, there are multiple causes of neonatal hypertension (Table 1), with the most common being renal parenchymal and renovascular abnormalities. A well-established renovascular etiology is umbilical arterial catheter-associated hypertension, both with and without demonstrable thromboembolic events. Umbilical catheter placement is thought to disrupt vascular endothelium, resulting in decreased perfusion and increased renin and aldosterone production. Chronic lung disease or bronchopulmonary dysplasia (BPD) is the most common nonrenal cause of hypertension in premature infants, with an incidence ranging from 13% to 43% in neonates with BPD, especially in those severely affected. In fact, among very low birthweight infants, those with BPD are twice as likely to develop hypertension as those without BPD. In other …