Certified Extremely Low Birth Weight (C-ELBW) Practice Exam

Persistent pulmonary hypertension of the newborn happens when the normal fall in pulmonary vascular resistance after birth doesn't occur. The result is persistently high PVR, reduced pulmonary blood flow, and right-to-left shunting through the fetal channels (patent ductus arteriosus and foramen ovale), causing severe hypoxemia despite oxygen therapy. This captures the idea of a disrupted transition to extrauterine circulation with ongoing elevated PVR.

Meconium aspiration syndrome can trigger PPHN, and the condition is classically seen in term or near-term infants rather than preterm, so that statement isn’t accurate. Diagnosis is not made by chest X-ray; echocardiography demonstrating elevated pulmonary pressures and shunting is the key.