Question

Discuss typical signs of normal and abnormal fetal heart rate (FHR) patterns

Answer 1

What is FHR OR FETAL HEART RATE MONITORING?

There are devices which are used to monitor fetal heart rate in the womb, fetal heart rate should be monitored on a regular basis during the last trimester of pregnancy or during delivery of the foetus.

the normal heart rate of the foetus which is considered normal is 110 to 160 beats per minute during the third trimester.

various types of devices which is used to monitor fetal heart rates such as external devices or internal devices.

Most often external devices are used to monitor fetal heart rate, for example, ultrasonography cardiotocography & foetoscope.

Internal devices are also used to monitor fetal heart rate by attaching a monitor directly to the foetus scalp to get the accurate measurement of fetal heart rate.

During monitoring of fetal heart rate nurses & doctors should be able to differentiate in between normal and abnormal fetal heart rate, differentiating between the normal and abnormal heart rate doesn't only reveal the condition of the foetus in the womb but it also tells if the mother is also at the risk of certain complications, early detection of abnormal heart rate prevents mother and foetus from any complication by taking action immediately.

The interpretation of the fetal heart rate is done on the following basis.

1. Importance of normal FHR.

It tells the condition of the foetus in the womb, a normal FHR is the sign that the foetus condition is good inside the womb.

2. Baseline heart rate.

Normal: a normal baseline is 110 to 160 beats per minute.

Abnormal:

There should not be any declarations during uterine contraction.

3. Accelerations have seen in FHR report.

Normal

Accelerations are considered normal and it is monitored during labour, it is the short term elevation in the rate of foetus heart, it is important for the doctors and the nurses to check acceleration as it reveals the well being of the foetus,

Abnormal

Acceleration is the sign of adequate oxygen supply to the foetus in the womb if acceleration is not seen, it is induced by the doctors to stimulate baby.

It is induced by:

1. Massaging the mother's abdomen gently.

2. Head of the baby is tapped with the finger through the cervix.

3. Stimulation with the sound.

4. Making mother hydrated by administering fluid.

3. Declarations.

As like acceleration, declarations are also considered normal but to a certain extent,

There are 3 types of declarations that can be seen during FHR.

Normal:

Early Declarations.

Early Declaration is not considered harmful as it can be seen during the initial phase of labour pains when baby head descends into the birth canal, it is also seen when baby's head is compressed due to the contraction or when the baby is premature.

Abnormal:

Late declarations begin only after the contraction is on the peak, late deceleration should be taken into consideration only when the baby's heart rate is compromised and not getting enough oxygen,

late deceleration considered normal if the baby is not compromised with oxygen.

Variable declarations.

A continuous fall and the irregularities in the heart rate of the foetus is seen during the labour pains, it is more often seen when the umbilical cord of the foetus is compressed and the baby does not get enough nutrients and oxygen,

During this period the doctor may take a decision to perform a caesarean section, or it may be delayed only when acceleration is seen.

Procedure to perform fetal heart rate.

External monitor.

1. Non-stress test.

A device called cardiotocograph is used to monitor fetal heart rate and the movement of the baby in the womb, a Doppler is attached in the mother womb with the cardiotocograph machine, it is monitored for 10 to 15 mins during the third trimester to know the well being of the baby in the womb.

2. Foetoscope.

It is a hollow device directly placed on the mother's womb and heard by the nurses and the doctors.

Internal devices.

A transducer attached with the wire is placed on the scalp of the foetus near cervix and heart rate is monitored through the device, the measurements done by the internal devices are more accurate and reliable than external devices.

Fetal heart rate should be monitored on a regular basis during the third trimester and continuously during labour pains and delivery, any complication seen should be reported immediately or should be taken into consideration.