Prolonged labor is a key risk factor for birth asphyxia because it can lead to reduced uteroplacental blood flow and fetal oxygen deprivation. During extended labor, the fetus may experience repeated episodes of compression and hypoxia, increasing the likelihood of insufficient oxygen delivery to vital organs. This results in a higher risk of neonatal complications such as hypoxic-ischemic encephalopathy. Timely recognition and management of prolonged labor are crucial to prevent asphyxia.

Reference: Williams Obstetrics, Cunningham et al., 25th Edition.