Foetal Echocardiography

Finding out that your baby has a Congenital Heart Disease (CHD) can be a shock for any parent. Unfortunately, with a rate of occurrence of 1 in every 100, it is a fairly common health complication. Finding out about a CHD earlier on in a pregnancy can help improve the outcome of the pregnancy. A foetal abnormality which is diagnosed early on helps a doctor plan the birth, manage any complications presented during the birth as well as schedule any surgeries that the new born may require.

A Foetal echocardiogram is a test that uses ultrasonic sound waves to evaluate the foetal heart for problems during the pregnancy itself. The test is most often done during the second trimester of pregnancy at around 18 to 24 weeks, and thoroughly examines the baby’s heart to reveal CHDs, as well as their degree of seriousness.

What Is Foetal Echocardiogram Or Echocardiography?

An ultrasound is done with the help of a hand-held device known as the proble. The probe moves over the area, sending out high frequency sound waves. These ultrasonic waves bounce off the structure of the foetal heart, which are then picked up by the probe and relayed to a monitor which uses it to make a 3D picture of the heart, its structure, walls and valves. It is not a routinely performed test and this is because the basic presence of foetal heart development is detected in routine prenatal ultrasound tests and most pregnancies do not require any more tests.

Foetal echocardiography is used in cases where there is a suspicion of foetal heart problems, since this helps in detecting heart abnormalities way before birth and allows for faster medical as well as surgical intervention. This diagnosis also improves the chance of survival after delivery for babies with severe heart defects.

When Foetal Echo Test Is Recommended?

Regular obstetric scanning during prenatal check-ups are capable of making a limited evaluation of the foetal heart which is generally sufficient for women at low risk for babies with CHDs. However, women who have one or more of these risk factors are usually asked to take a detailed foetal echocardiogram:

• If there is any family history of CHD, in near relatives like parents or grandparents
• If a sibling was born with a CHD
• If a routine prenatal ultrasound has discovered possible heart abnormalities
• If the mom has alcohol or drug dependency
• If the mother has health issues like diabetes, lupus or phenylketonuria
• If the mother has contracted rubella during her pregnancy
• A prenatal ultrasound has shown other congenital anomalies which require investigation
• If prescriptions for acne or anti-seizure medications have been taken by the mother

When Is It Done?

A foetal Echocardiogram is generally done around the second trimester, around 18 to 24 weeks. It is also done at any other time when the doctor discovers a potential anomaly during routine prenatal check-ups done to follow foetal growth, and monitor foetal well-being.

What Preparation Is Required For Foetal Echo Test?

No preparation is required, a full bladder or an empty stomach are not needed. Since the test can be quite long and in some cases may take up to 2 hours, eating a meal before the test and keeping snacks at hand is a good idea.

How Is The Foetal Echo Scan Performed?

A foetal echocardiography ultrasound is a test performed with a hand-held probe known as a transducer. An ultrasound sonographer performs the test, although sometimes a maternal-foetal medicine specialists or perinatologist can do it too. The images are interpreted by a pediatric cardiologist specializing in CHDs. The test uses an ultrasonic transducer probe in order to obtain images of different structures and locations of the foetal heart. The techniques used are:

Abdominal Echocardiography

This is the most common form of ultrasound imaging. During the foetal echocardiogram procedure, a clear gel is applied to the mother’s abdomen and the hand held probe is moved over it to take pictures from various angles. The test can take from 45 minutes to 2 hours depending on the stage of development of the foetus, the complications in identifying the problem as well as its complexity.

Transvaginal Echocardiography

A Transvaginal or Endovaginal probe is used when an issue is suspected in the early weeks of foetal development, when the underdeveloped foetus requires more proximity for the detection of the issue. The probe is inserted into the vagina and imaging is attempted from this angle for better results.

Other Techniques

• 2-D echocardiography – A cone-shaped echo view of the actual structures and motion of the heart is done. This information on the motion and working of the foetal heart tells us more about the efficiency of the heart and its ability to actually pump blood properly.
• Doppler echocardiography – The pace of the blood flow through the heart’s valves and chambers and abnormal blood flow in the heart are detected.

What About Results Of The Foetal Echo Test?

If the results of a foetal echo are normal, the patient is discharged and asked to come back if later prenatal test require it. If there is a problem with the quality of the pictures because of the growth stage of the foetus, you may need a follow up echo at a later date. If there is a heart defect, you may need to consult with a pediatric cardiologist to understand the test results and for detailed diagnosis and counselling.

What Are The Limitations Of Foetal Echocardiography?

In the cases of test performed between 12–18 weeks, there may need to be follow up testing performed at a later date to get more definitive pictures to confirm the findings on the early study. There may be a need for more follow up tests and consultations like:

• A Foetal MRI and a high level foetal ultrasound to check the overall health of the foetus and to see if there are abnormalities in other organs
• Amniocentesis to check for genetic and chromosomal disorders
• Consultations with Geneticists and genetic counsellors to know the consequences and management methods for a heart disorder
• Consultation with a perinatologist to find out how you can manage your pregnancy and to make plans for delivery

Importance Of Foetal Echocardiography

Since many foetal heart defects can be repaired before delivery, it is good to find out if there is a problem at an early stage. Early diagnosis also helps in scheduling the birth of the baby with an attending neonatal unit, and if required a surgical team to make any intervention necessary (like surgery) as early as possible to give your baby a better chance of good health lifelong.

Conclusion: Thus, detecting the foetus’ heart problem well in advance can help you avert a possible abortion. It is important that you get it diagnosed much in advance so that you can take the required precautions.

Read this article in Arabic: ضربات قلب الجنين