Fetal Heart Rate Monitoring

Fetal monitoring is the way to displays the fetal heart rate (FHR). Fetal heart rate is monitored in relation to maternal contraction. The baseline FHR is measured between contraction and the normal FHR at term is 120-160 beats per minute. The device that monitors uterine activity can assess frequency, duration and intensity of contractions.

There are two types of fetal monitoring: external fetal monitoring and external fetal monitoring.

External Fetal Monitoring
It is noninvasive procedure and is performed using a tocotransducer or Doppler ultrasonic tranducer. The ultrasound transducer is placed over the area in which the fetal back is located and fasten with a belt. The tocotransducer is placed over the fundus of uterus where contractions feel stronger and fasten with a belt. This external fetal monitoring will allow the client to get position comfortably.


Internal Fetal Monitoring It is invasive procedure and requires rupturing of the membranes and the electrode is attached to the presenting part of the fetus. For being available of internal fetal monitoring, the mother must be dilated 2-3 cm.

FETAL HEART RATE PATTERN

Fetal Bradycardia:
The FHR is less than 120 beats per minute for 10 minutes of more

Fetal Tachycardia:
The FHR is greater than 160 beats per minute for 10 minutes or more.

Acceleration
Accelerations are temporary increases of FHR at least 15 beats greater than the baseline and lasting at least 15 seconds, reflect a responsive nonacidotic fetus. Acceleration may occur with fetal movement, uterine contraction, vaginal examinations, or when the fetus is in a breech presentation.

Early Decelerations
In early decelerations, the fetal heart rate is below baseline and return to the baseline by the end of the contraction. It usually occurs during contractions and not associated with fetal compromise and requires no interventions. A uniform shape and mirror image of uterine contraction are showed.

Late Decelerations
In late decelerations, the fetal heart rate looks similar to early deceleration but begin well after the contraction begins and return to baseline after the contraction ends. Late decelerations reflect impaired placental exchange or uteroplacental insufficiency. The intervention includes improving placental blood flow and fetal oxygenation by placing patient on side, administer oxygen by tight face mask, discontinue oxytocin (if any), hydration, and correct hypertension (if any).

Variable Deceleration
In variable decelerations, the fetal heart rate does not have the uniform appearance. Shape, duration and degree of FHR fall below baseline are variable. Variable decelerations are significant when the FHR repeatedly decreases to less than 7- beats per minutes and persists at the level for at least 60 seconds before returning to the baseline. The cause of variable decelerations is the conditions that restrict flow through the umbilical cord (compressed umbilical cord). Interventions include change position (trendelenburg may be helpful), discontinue oxytocin (if any), check for cord prolapsed or imminent delivery by vaginal exam, consider amnioinfusion, and administer 100% oxygen by tight face mask.