Fetal Response to Interrupted Oxygenation

Class,

In my last posting, I discussed the environmental causes of interrupted oxygenation to the fetus. This post we will discuss the fetal response to interrupted oxygenation. What information can the fetal heart tracing provide regarding transfer of oxygen?

Interruption of the pathway of oxygen transfer from the environment to the fetus caused by compression of the umbilical cord can result in a variable deceleration.

Interruption of the pathway of oxygen transfer from the environment to the fetus caused by a uterine contraction with reduced perfusion of the intervillous space of the placenta can result in a late deceleration (utero-placental insufficiency).

Interruption of the oxygen pathway at any point can result in a prolonged deceleration.

What do we know about the fetal response to interrupted oxygen transfer?

The fetal response to interrupted oxygenation follows this pathway:

FETUS

↓

HYPOXEMIA

↓

HYPOXIA

↓

METABOLIC ACIDOSIS

↓

METABOLIC ACIDEMIA

↓

POTENTIAL INJURY

Please think about some of the potential injuries you might see with progressive interrupted oxygenation to the fetus and post your response.