Fetal Heart Arrhythmia: Symptoms and Treatment

During pregnancy, expectant parents eagerly anticipate the sound of their baby’s heartbeat during prenatal check-ups. While most pregnancies progress with a regular and rhythmic heartbeat, some babies may experience fetal heart arrhythmia, which are irregularities in the baby’s heart rate or rhythm. Although fetal arrhythmias can be concerning for parents, it’s essential to understand that many cases are benign and can resolve on their own. In this article, we explore what fetal arrhythmia is, its causes, potential risks, and how it is managed.

What is Fetal Heart Arrhythmia?

An arrhythmia is an irregular heart rate or rhythm. The heart may beat too fast or too slow, or otherwise outside the norm. Fetal arrhythmia refers to any abnormality in the baby’s heart rate or rhythm while still in the womb. It can manifest as either a slower or faster heartbeat than the normal range or as irregular beats. Detecting fetal heart arrhythmia often occurs during routine prenatal check-ups when the healthcare provider listens to the baby’s heartbeat using a fetal Doppler or ultrasound.

Usually, fetal arrhythmia is benign. However, the healthcare provider may insist on close pregnancy monitoring because, without treatment, this condition may lead to serious problems, including preterm delivery or even death.

Causes of Fetal Arrhythmias

Expectant mothers may notice that the baby’s heart beats faster than their own. In fact, a normal fetal heart rate ranges between 110 – 160 beats per minute. It should be noted that fetal heart rates may change and vary from beat to beat. To learn more, read the general guidelines for the normal fetal heart rate by week range at different stages of pregnancy. The causes of fetal heart arrhythmia can vary and may include:

• Immaturity: In early pregnancy, fetal arrhythmias can be linked to the developing heart’s immaturity as it establishes its regular rhythm.
• Maternal factors: Certain maternal conditions, such as diabetes or thyroid disorders, can influence the baby’s heart rate.
• Structural heart defects: In some cases, fetal arrhythmias may be associated with structural heart abnormalities.
• Medications: Some medications taken by the mother during pregnancy may affect the baby’s heart rate.
• Infections: Sometimes, fetal heart arrhythmia may be linked to the mother’s infections in the first trimester, such as rubella, parvovirus b19, or cytomegalovirus.

A structural heart defect may not always be the cause of fetal arrhythmias. Instead, they can be caused by inflammation or electrolyte imbalances.

Potential Risks and Complications:

In many instances, fetal arrhythmias pose minimal risk to the baby and may resolve on their own. However, in some cases, depending on the type and severity of the arrhythmia in fetus, potential risks may include:

• Preterm birth: Severe or persistent arrhythmias could lead to the decision to induce labor prematurely for medical reasons.
• Heart failure: In rare cases, severe fetal heart arrhythmia could potentially strain the baby’s heart, leading to heart failure.
• Structural heart abnormalities: Fetal arrhythmias may indicate underlying structural heart issues that may require medical attention after birth.

How Fetal Heart Arrhythmia Diagnosed?

When your healthcare provider suspects an arrhythmia, it is necessary to do more detailed imaging called a fetal echocardiogram. It helps to visualize the structures of the heart, blood flow, and other features to help with diagnosis. Fetal echo is a noninvasive test that is done as an abdominal ultrasound by a trained sonographer. Such tests can be performed as early as 12 weeks into pregnancy but are more reliable after 17-18 weeks. Also, irregular heartbeat in fetus can be detected with at home fetal doppler. Find out about fetal dopplers in more detail, read this excellent guide on How to Use a Fetal Doppler at Home: 8 Tips and Tricks.

Management and Treatment:

The management of fetal arrhythmias involves close monitoring and, in some cases, specific interventions. Treatment will depend on the type and severity of the fetal heart arrhythmia, as well as the baby’s overall well-being. Some common approaches include:

• Ongoing monitoring: Regular prenatal check-ups with fetal heart rate monitoring allow healthcare providers to assess the baby’s heart rhythm and rate over time.
• Additional tests: In some cases, further evaluation through fetal echocardiography (an ultrasound of the baby’s heart) may be recommended to assess heart structure and function.
• Medication: In severe cases, medication may be prescribed to regulate the baby’s heart rate and rhythm.
• Interventional procedures: In rare instances, specialized procedures such as fetal cardiac catheterization may be required.
• Timing of delivery: In some cases, the timing and mode of delivery will be carefully planned to minimize potential risks associated with the arrhythmia.

Conclusion

Fetal heart arrhythmia, while potentially concerning for parents, can often be benign and resolved on their own. Regular prenatal care, including fetal heart monitoring and evaluation, is essential in identifying and managing these irregularities effectively. Parents should communicate openly with their healthcare providers to ensure the best care for the mother and the baby throughout pregnancy and beyond.