How is a fetal echocardiogram done?
The test is typically performed by a specially trained ultrasound sonographer, and the images are interpreted by a pediatric cardiologist who specializes in fetal congenital heart disease. A limited evaluation of the fetal heart is possible during regular obstetric scanning and is appropriate for women at low risk. However, women who have one of the risk factors listed above should have a detailed fetal echocardiogram.
There are two ways to perform a fetal echocardiogram:
- Abdominal ultrasound: This is the most common form of ultrasound to evaluate the baby's heart. A gel is applied to the woman’s abdomen, the ultrasound probe is gently placed on the abdomen and pictures are taken. This test is not painful and causes no harm to the fetus. The test takes approximately 45–120 minutes depending on the complexity of the fetal heart.
- Endovaginal ultrasound: This ultrasound is typically used early in pregnancy. A small ultrasound transducer is inserted into the vagina and rests against the back of the vagina. Pictures can then be taken of the fetus's heart.
Is there any preparation needed for the test?
Unlike some routine prenatal ultrasounds, a full bladder is not necessary for a fetal echocardiogram, and there is no special preparation needed. You may wish to bring your medical information as that may be helpful to your health care team. The study can take anywhere from 30 minutes to over two hours.
When will the test be done?
The test is recommended at 18 to 22 weeks for all patients who have a CHD and partners of men who have a CHD. The test may be completed earlier in pregnancy in parents with high rates of CHD in their family or more severe cardiac defects.
What will the results show?
At your follow-up appointment your health care professional will discuss the results of your test. If the test is normal, no cardiac abnormalities were found. You will continue with routine pregnancy care and testing.
Abnormal results will tell you whether there is a problem with the way the fetus’s heart works or formed. It can also tell you whether there are abnormal heart rhythms (arrhythmias). If abnormal results are found, you may need to undergo further testing and generally will be referred to a specialist who can treat the condition.
Even in the case of a normal study, you will be counseled that not all heart problems can be ruled out. This is because circulation in the fetus is different than after birth. Additionally, very small holes between the lower chambers of the heart are hard to see and it may not be possible to see every part of the large blood vessels from the fetus’s heart.
The diagnosis of heart defect has significant implications for the overall health of the fetus. These health issues may have significant implications for the prognosis of the child and play a major role in helping you make decisions about your pregnancy. Your cardiologist will provide you with information about whether you need to worry about these other issues; however, when the concern is significant you will be referred to other members of the care team that work closely with the pediatric cardiologist.
Other tests, procedures and referrals that may be needed include the following:
- Fetal ultrasounds: A detailed ultrasound of the rest of the fetus is necessary to follow fetal growth, monitor fetal well-being and assess the rest of the fetus for abnormalities in other organs.
- Cardiac MRI: This test is becoming more widely available and can provide additional information about the overall health of the fetus and problems with certain organs.
- Amniocentesis: This is a test performed to determine chromosomal and genetic disorders and certain birth defects. The test involves inserting a needle through the abdominal and uterine wall into the amniotic sac to retrieve a sample of amniotic fluid.
- Genetic counseling: Geneticists and genetic counselors provide an assessment of the likelihood of a genetic syndrome and possible abnormalities in other organs based on the heart diagnosis and other findings in the fetus. The geneticist can provide information to patients and their relatives concerning the consequences of a disorder, the probability of developing or transmitting it, and ways in which it can be prevented, treated, and managed.
- Specialist consultation: Depending on the diagnoses you may be referred to other subspecialists including a maternal-fetal medicine specialist, pediatric cardiologist, neonatologist and geneticist.
- Social worker/nurse: Someone who is familiar with heart disease in children can provide information about caring for a child with congenital heart disease.