In persistent pulmonary hypertension of the newborn (PPHN), what condition is primarily affected?

Persistent pulmonary hypertension of the newborn (PPHN) primarily affects term infants. This condition is a serious and often life-threatening issue in which a newborn's circulation system does not properly transition to breathing air after birth.

In a healthy transition, the blood vessels in the lungs dilate to allow blood to flow and pick up oxygen. However, in PPHN, these vessels stay constricted, leading to high blood pressure in the lungs and decreased oxygen levels in the bloodstream. PPHN often arises due to various factors including meconium aspiration syndrome, respiratory distress syndrome, and other perinatal factors typically associated with term infants.

While preterm infants can face an array of different respiratory complications, they are not the primary demographic affected by PPHN. The incidence is significantly higher in term infants compared to preterm or those with severe birth defects, who are affected by different pathophysiological mechanisms.