What condition are postterm neonates at an increased risk for due to placental degeneration?

Postterm neonates are indeed at an increased risk for perinatal asphyxia primarily due to placental degeneration, which typically begins to occur after the 42-week mark of gestation. During this time, the placenta may become less effective in delivering nutrients and oxygen to the fetus, resulting in a compromised supply. This reduction in blood flow and oxygen can lead to fetal distress, ultimately increasing the likelihood of asphyxia during labor and delivery.

The placenta’s deterioration can lead to complications such as decreased amniotic fluid levels, which further impacts fetal well-being. These factors combined make it critical to monitor postterm infants closely for signs of asphyxia, which can manifest as low Apgar scores or abnormal fetal heart rate patterns.

Other conditions such as hyperglycemia, neonatal jaundice, and respiratory distress syndrome can arise in different contexts but are not as directly associated with placental degeneration specifically in the postterm scenario. Understanding the dynamics of placental function and its timing in relation to gestation is key to grasping why perinatal asphyxia is of particular concern in this population.