External Electronic Fetal Monitoring: What Does It Tell You?

External electronic fetal monitoring is a non-invasive procedure that uses special equipment to monitor the baby's heartbeat and the mother's contractions during pregnancy and labour. It is usually carried out when the pregnancy is deemed high-risk or when there are other reasons to check the baby's heart rate. The procedure involves placing an ultrasound transducer and a pressure-sensitive gauge on the mother's abdomen, which are connected to a monitor that displays the data on a screen or paper. This allows healthcare providers to assess the baby's health and safety and determine if any interventions, such as a change in position or an emergency C-section, are necessary. While external electronic fetal monitoring is a common procedure, it may have limitations in certain situations, such as when monitoring obese women or multiple gestations.

The baby's heart rate

Doctors will typically monitor the baby's heart rate later in the pregnancy and during labour. Monitoring may also be done during pregnancy, especially after trauma to the belly, to assess the health of the fetus. If a traumatic event occurs after 20 weeks of gestation, providers may recommend monitoring for a period of 4 to 24 hours.

Types of Heart Rate Monitoring

There are two main types of fetal monitoring:

• Intermittent Auscultation: This involves periodically listening to the baby's heartbeat at set times throughout labour by pressing a special stethoscope or Doppler device against the mother's belly. If there are problems during labour, the baby's heart rate may be checked more frequently.
• Electronic Fetal Monitoring (EFM): This involves continuously monitoring the baby's heartbeat and the mother's contractions during labour. EFM is considered the current gold standard method for determining the fetal heart rate.

For external monitoring, providers may use a fetoscope (a special type of stethoscope) or a Doppler device. The Doppler uses sound waves and a computer to detect the baby's heartbeat. For internal monitoring, a small wire (electrode) is placed on the baby's head while they are still inside the uterus.

A healthy baby's heart usually beats between 110 and 160 times a minute in the womb. It speeds up when the baby moves. Signs of possible problems include:

• Heart beats slower than 110 beats per minute
• Heart beats faster than 160 beats per minute
• An abnormal heartbeat pattern
• Lack of increase in heart rate when the baby moves or during contractions

However, an abnormal fetal heart rate does not always mean the baby is in danger. It could be a result of the baby's position, or the mother's or baby's movement.

Risks and Benefits of Heart Rate Monitoring

External monitoring is generally considered low risk and does not cause any physical discomfort. Internal monitoring carries a slight risk of infection and may cause a small mark or cut on the baby's head, which usually heals quickly.

Electronic fetal monitoring may restrict the mother's movement and ability to labour in different positions. It can also lead to false alarms, causing stress for the mother. Some research suggests that continuous EFM may increase the risk of C-section and other interventions compared to intermittent monitoring.

Monitoring the baby's heart rate during labour and delivery provides valuable information about the baby's health and well-being. While external monitoring is generally preferred, internal monitoring may be necessary in certain situations or when more precise monitoring is needed.

The baby's health

Electronic Fetal Monitoring (EFM) is a continuous test that records the mother's contractions and the baby's heart rate. It is a very common procedure and can be done in two ways: externally, on the outside of the mother's belly, or internally, directly on the baby while inside the uterus. External monitoring is the most common type.

Healthcare providers use elastic strips to secure two measuring devices to the mother's abdomen. An ultrasound device positioned over the abdomen measures the baby's heart rate, while a pressure gauge placed at the top of the abdomen measures the frequency of the mother's contractions. The devices connect to an external monitor that records the activity on an electronic or paper readout.

EFM ensures the baby's health and safety during labour and delivery. It provides real-time, continuous information about how the baby is doing and can indicate fetal distress. By monitoring the baby's heart rate, providers can identify concerns and take steps to protect the baby. For example, if the heart rate is abnormal, providers may ask the mother to change positions to help the baby get more oxygen.

EFM is typically done during labour and delivery, but it can also be used before labour to assess the health of the fetus, especially after trauma to the mother's belly. If a traumatic event occurs after 20 weeks of gestation, providers may recommend monitoring for a period of 4 to 24 hours.

Who Is It For?

EFM is widely used by providers, but experts recommend it only for pregnancies that are at high risk of complications. The latest recommendations from the American College of Obstetricians and Gynecologists call for EFM when labour is induced or assisted with medication, and in pregnancies considered high risk due to maternal health conditions, meconium staining during labour, small fetal size, or congenital abnormalities.

Some studies have found that routine EFM increases the rates of unnecessary cesarean sections and deliveries using vacuum devices or forceps. It can also lead to false alarms, restrict movement during labour, and lead to a false concern for fetal distress resulting in unnecessary interventions. Internal EFM carries additional risks, including injury to the baby's scalp and the transmission of infections such as HIV or genital herpes.

The mother's contractions

External electronic fetal monitoring (EFM) is a continuous test that records the mother's contractions and the baby's heart rate. It is usually carried out during labour and delivery, but can also be used earlier in the pregnancy.

The frequency and power of the contractions are recorded on a monitor, which can be viewed on a screen and printed onto paper. This information can be used alongside the baby's heart rate to determine the best course of action for the mother and baby.

If the mother's contractions are causing distress to the baby, the healthcare provider may ask the mother to change position to help the baby get more oxygen. If this does not help, the provider may consider an immediate caesarean section or vaginal delivery using a vacuum device or forceps.

Whether the mother needs to change position

External electronic fetal monitoring (EFM) is a continuous test that records the mother's contractions and the baby's heart rate. It is usually carried out when the pregnancy is considered high-risk.

Whether or not the mother needs to change position depends on the type of EFM being used. External EFM involves the use of elastic strips to secure two measuring devices to the mother's abdomen. This restricts the mother's movement to her bed and chair. However, some hospitals offer wireless telemetry monitoring, which allows the mother to move around more freely.

If internal EFM is being used, a wire is inserted through the mother's vagina and attached to the baby's head. With internal EFM, the mother will need to stay in bed.

In some cases, changing position may be recommended if there are concerns about the baby's heart rate or if the baby is experiencing distress. Changing position may help to improve blood flow to the baby.

Whether a C-section is required

External electronic fetal monitoring is a common procedure that can be carried out in two ways: externally, on the outside of the mother's belly, or internally, directly on the baby while inside the uterus. External monitoring is usually carried out with a device called a fetoscope (a specially shaped stethoscope) or a Doppler (an electronic tool that uses sound waves and a computer).

Electronic fetal monitoring (EFM) is a continuous test that records the mother's contractions and the baby's heart rate. It is used to indicate fetal distress during labour and delivery. It is recommended for pregnancies that are at a high risk of complications.

EFM can be used to determine whether a C-section is required. If a baby is in distress, a C-section may be necessary. Signs of distress include an abnormal fetal heart rate or pattern, which could mean that the baby is not getting enough oxygen. If abnormal readings continue, further tests can help determine the cause of the distress, and if there is a problem, a C-section will usually be performed.

Some studies have found that routine EFM increases the rates of unnecessary C-sections. False alarms are common with EFM, and can be caused by the transducer slipping out of place, the baby shifting position, or contractions suddenly increasing in intensity.

Frequently asked questions