Non-Reassuring Fetal Heart Rate
 
A non-reassuring fetal heart rate refers to an abnormal fetal heart rate which indicates the baby is experiencing lack of oxygen, suffering from fetal distress and my be developing damaging acidosis.

Electronic fetal heart monitoring is used to assess the baby's well-being during labor.  Monitoring may be done using an external fetal heart monitor or an internal monitor.  The fetal heart rate has certain characteristics that doctors, and nurses should use to determine the baby’s well being during labor and delivery. Fetal heart rate patterns are classified as: Reassuring- the baby is oxygenated and tolerating labor and delivery well; Non-reassuring - the baby is showing signs of lack of oxygen and may be developing acidosis; and Ominous-the baby is in danger and requires immediate resuscitation and delivery.

Fetal heart rate characters include the baseline rate; variability; decelerations;accelerations.
 
Baseline fetal heart rate is the average fetal heart rate over 10 minutes between uterine contractions, decelerations, or accelerations.  In a term infant, the normal baseline fetal heart rate is typically between 120 and 160 bpm (beats per minute).

Tachycardia is a abnormal fetal heart rate that is above 160 bpm that lasts for at least 10 minutes. Tachycardia may be a sign of lack of oxygen in the baby.

Bradycardia is a abnormal fetal heart rate that is below 110 bpm that lasts for more than 10 minutes.  Bradycardia with loss of variability and late decelerations may be predictive or current or impending fetal hypoxia. 

Variability refers to the fluctuation of the fetal heart rate, Loss of variability indicates lack of oxygen.

Acceleration is a increase in the fetal heart rate from the baseline rate.

Deceleration is a decrease in the fetal heart rate from the baseline rate. There are different types of decelerations. Some type indicate the baby is suffering from lack of oxygen.  

A late deceleration is a decrease in the fetal heart rate typically caused by uteroplacental insufficiency.

A baby has a limited time that he or she can withstand hypoxic conditions before suffering a brain injury.  That limited time is generally referred to as the fetal reserve.  The fetal reserve is not an absolute time and may vary somewhat among babies.  For this reason, it is very important for doctors and nurses to carefully monitor the fetal heart rate so emergency intervention occurs before the baby suffers a hypoxic-ischemic brain injury.

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