Histamine H2 blockers have been shown to increase the incidence of which condition in very low birthweight infants?

• A. Apnea of prematurity
• B. Necrotizing enterocolitis
• C. Pulmonary hypertension
• D. Intraventricular hemorrhage

Answer: (B)

Suppressing gastric acid in very low birthweight infants can increase the risk of necrotizing enterocolitis. When stomach acidity is reduced by H2 blockers, the gut is less hostile to bacteria, leading to altered intestinal microbiota and greater bacterial translocation across the immature gut barrier. This combination promotes inflammation and intestinal injury characteristic of NEC in this vulnerable population.

Other conditions listed have different causes not linked to acid suppression—apnea of prematurity relates to immature respiratory control, pulmonary hypertension to abnormal pulmonary vascular remodeling, and intraventricular hemorrhage to fragile germinal matrix vessels and fluctuating cerebral blood flow. The association between H2 blockers and NEC is the one most consistently observed in very preterm infants.