Which factor is a risk for PVL indicating reduced blood flow to the brain around birth?

• A. Hypoxia during adolescence
• B. Perinatal ischemia
• C. Postnatal dehydration
• D. Maternal iron deficiency

Answer: (B)

PVL occurs when there is reduced blood flow and oxygen delivery to the brain around the time of birth. In preterm infants, the periventricular white matter is especially vulnerable to hypoxia-ischemia; damage to the developing pre-oligodendrocyte cells in that region leads to the characteristic white-matter injury seen in PVL. When perfusion is compromised during the perinatal period, these cells die and demyelination or cystic changes develop near the ventricles.

Among the options, perinatal ischemia directly captures the timing and mechanism of the injury relevant to PVL. Hypoxia during adolescence happens well after birth and doesn’t explain PVL. Postnatal dehydration can affect perfusion but the critical, injury-causing event for PVL is the ischemic/hypoxic episode around birth. Maternal iron deficiency may influence fetal oxygen-carrying capacity but is not the specific perinatal hypoperfusion event that leads to PVL.