Blood brain barrier was damaged after neonatal hypoxic–ischemic (H/I) brain injury.
n‐3 PUFA preserved the integrity of blood brain barrier following H/I.
n‐3 PUFA alleviated degeneration of tight junction after neonatal H/I insult.
n‐3 PUFA suppressed H/I induced activation of MMP-9 and MMP-2 both in brain and in blood.