What Is A Fetal Echo?

Reviewed by Dan Brennan, MD on November 27, 2021

Fetal echo is short for fetal echocardiogram, an ultrasound test doctors use to look for congenital heart disease (CHD). This disease affects around 1% of births each year and encompasses a wide range of heart issues. The most common CHD diagnosis is called ventricular septal defect (VSD).

Understanding A Fetal Echo

The probe used in a fetal echocardiogram is called a transducer. It emits ultrasonic sound waves into your belly that create an image on the doctor’s screen. These sound waves are at a frequency that moves through your skin and your baby’s skin to bounce off the heart structures.

This type of test doesn’t cause pain or harm to you or your baby. It usually takes between 30 minutes and 2 hours to complete because of the complexity of an infant’s developing heart and the number of things a doctor is looking for.‌

The fetal echocardiogram is very similar to other ultrasounds done during pregnancy. It differs because it is used solely to look at your baby’s heart and no other structures.

What Happens During a Fetal Echo?

An ultrasound technician completes the exam and imaging. A pediatric cardiologist reads and interprets the images as a specialist who understands your baby’s heart development in the womb.

Doctors do the ultrasound while your baby is in the womb, because 25% of infants with CHD need medication or surgery within the first year of life. Early detection allows doctors to prepare for your infant’s care and ensure they have a plan in place.

Preparing for a fetal echo. Some ultrasounds require you have a full bladder for better results. That isn’t necessary for a fetal echocardiogram. In fact, you may prefer to empty your bladder prior to the exam since it can take up to 2 hours to complete.

Because your doctor makes a referral to a specialist, it’s important to have as much information as possible available for your technician. This may include details like:

  • Your own heart defect
  • Family history of heart defects
  • Medical records ‌
  • Details of your concerns

Why a Fetal Echo Is Important

Fetal echos check for congenital heart diseases that happen in the womb and may affect the structure and function of your baby’s heart. A mild CHD may be a hole in your baby’s heart, while a more severe case may have missing parts. Types of CHD include:

  • Atrial septal defect
  • Atrioventricular septal defect
  • Coarctation of the aorta
  • Double-outlet right ventricle
  • d-transposition of the great arteries
  • Ebstein anomaly
  • Hypoplastic left heart syndrome
  • Interrupted aortic arch
  • Pulmonary atresia
  • Single ventricle
  • Tetralogy of fallot
  • Total anomalous pulmonary venous return
  • Tricuspid atresia
  • Truncus arteriosus
  • Ventricular septal defect

Results of a Fetal Echo

A pediatric cardiologist gives you and your doctor the results of the ultrasound. You may get the answers you need from the test, or you may be left with more questions. It depends on the gestational age of the baby, the diagnosis, and the quality of the imaging.

Once the study is complete, you meet with the pediatric cardiologist to learn about the findings. You may need one or several tests done before your baby’s birth to monitor the severity of the condition. This is true even if your first test offers results within a normal range.

Fetal echocardiograms are considered reliable after 17 weeks gestation, although they may be completed vaginally instead of abdominally as early as 12 weeks. If a heart defect is spotted, you’ll learn about the best- and worst-case scenarios for your baby.

This helps you prepare for what needs to happen after birth. In some cases, babies need monitoring or surgery right after birth for stabilization. Your doctor gives you all available options, educates you on the possible outcomes of each, and allows you and your partner to make the best decision.

Congenital heart diseases may raise your baby’s risk of other genetic problems like Down syndrome or DiGeorge syndrome. Benign tumors may show up along with heart conditions, signifying tuberous sclerosis.

Other tests may include:

  • High-level fetal ultrasound, a more detailed ultrasound to look for other abnormal signs
  • Fetal MRI, which looks at the development of your baby’s organs
  • Genetic counseling, an assessment that determines the likelihood of a genetic condition, including the probability that future children will have a similar condition ‌
  • Amniocentesis, which determines chromosomal disorders, genetic disorders, and some birth defects based on your infant’s DNA while still in the womb

Risks of a Fetal Echo

Fetal echocardiograms are safe for both mother and baby. This type of ultrasound doesn’t pose significant risks. However, not completing a recommended test may leave your baby at risk following birth.

Show Sources


American Heart Association: “Fetal Echocardiogram Test.”

Centers for Disease Control and Prevention: “What are Congenital Heart Defects?”

Kids’ Health: “Fetal Echocardiogram.”

Texas Children’s Hospital: “What's a fetal echocardiogram?”

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