What is a Fetal echocardiography ?
This is an ultrasound screening test for evaluation of structure of fetal(unborn baby’s) heart. Congenital heart disease (CHD) has a prevalence of 8.2 per 1000 live births and is a leading cause of infant morbidity and mortality. This test can detect problems with the heart such as defects or arrhythmias.
Who should get this test done ?
Fetuses identified as having, or suspected of having, an abnormality on routine cardiac ultrasound screening are candidates for a fetal echocardiogram and for fetuses with a significant risk factor for CHD, i.e. when their risk is elevated above that of the general population(Listed below, ISUOG practice guidelines https://doi.org/10.1002/uog.26224)
Fetal factors
1. Suspected cardiac structural anomaly
2. Fetal extracardiac anomaly known to be associated with CHD
3. Suspected abnormality of cardiac function or cardiomegaly
4. Hydrops fetalis
5. Persistent fetal tachycardia (heart rate ≥ 180 bpm)
6. Suspected heart block or persistent fetal bradycardia (heart rate ≤ 110 bpm)
7. Frequent episodes or persistently irregular cardiac rhythm
8. Nuchal translucency ≥ 3.5 mm
9. Confirmed or suspected genetic abnormality
10. Monochorionic twinning
Patient or familial disease or environmental exposure
> First-degree relative of fetus with CHD (parents, siblings, half-siblings)
> First- or second-degree relative with disease of Mendelian inheritance and history of childhood cardiac manifestations
> Pregestational diabetes, regardless of HbA1c level
> Anti-Ro/SSA antibodies
> Phenylketonuria (unknown status or periconceptional phenylalanine level > 10 mg/dL)
> Retinoid exposure
> Confirmed fetal infection (TORCH- and parvovirus-B19-positive)
Other indications when fetal echo may be considered
Second-degree relative of fetus with CHD
Gestational diabetes diagnosed in first or early second trimester
Nuchal translucency between 3.0 and 3.4 mm
Selected teratogen exposure (e.g. paroxetine, carbamazepine, lithium, sodium valproate)
Conception by IVF, including ICSI
Use of ACE inhibitors (antihypertensive medication)
Other considerations
Though historical reports may suggest otherwise, there is insufficient evidence to show that risk of CHD is significantly over baseline for certain patient and fetal factors, including: patient obesity (BMI ≥ 35 kg/m2), SSRI antidepressant exposure other than paroxetine, non-cardiac ‘soft marker’ for aneuploidy, abnormal serum analytes (e.g. α-fetoprotein level), isolated SUA, gestational diabetes diagnosed after second trimester, warfarin exposure, alcohol exposure, echogenic intracardiac focus, prenatal fever or viral infection with seroconversion only, isolated CHD in a relative further removed than second-degree to fetus.
Ultrasound imaging uses soundwaves to take pictures. It is radiation free and is not harmful to you or your unborn baby. The preferred timing for fetal echocardiography is 20-24 weeks of pregnancy
What is to be done prior to exam?
Kindly take appointment at least one day prior to exam.
It is helpful to hold off on using any creams or lotions on your belly on the morning of your test. If you have had any previous tests, such as a past ultrasound, bring any medical records that you have.
Kindly turn off your phone/keep it in silent mode before entering the ultrasound room and throughout the examination.
What will happen during the examination?
The scan will be performed in dimly lit room and you would be asked to lie on a flat couch. Clear(perhaps cold) ultrasound gel will then be applied and the ultrasound specialist will commence the exam. To get optimum views of your baby, slight pressure may have to be applied.
A fetal echocardiogram can also be performed using an endovaginal ultrasound. During this type of test, a small ultrasound transducer is placed inside the vagina to obtain pictures of your baby’s heart. This is not painful or harmful for the unborn baby. A transvaginal scan can be performed earlier in pregnancy and provides a clearer picture
The time duration varies, but is usually between 30 -45min.
If your baby is not in a very easy position for the ultrasound specialist to see, you may be asked to wriggle your hips, jump up and down, walk around outside or come back at another time or date.
Benefits*
A fetal echocardiogram is an effective way to screen a baby for heart disease. Recent studies found that fetal echocardiography accurately detected congenital heart defects in around 85% cases.
Most babies are normal and healthy and most parents find the experience enjoyable and informative.
However if a defect is suspected:
It may help with discussion with parents about options of further testing, options of continuing or terminating the pregnancy
Prenatal diagnosis Prenatal diagnosis can improve birth outcome prior to intervention, particularly for certain types of cardiac lesion.
Prenatal awareness of CHD and parental education allow preparation for the birth of a neonate that will require specialized care and services.
The impact of prenatal diagnosis may also be relevant to long-term neurodevelopmental outcome and it maximizes options for the family.
*Scan at Fetal Experts Lucknow is done in accordance with international guidelines(ISUOG).
Limitations
Ultrasound alone cannot exclude all structural defects, chromosomal abnormalities and rare genetic disorders.
No obvious abnormality does not guarantee structural and functional normality of fetal heart in future.
There are some heart abnormalities that cannot be detected prenatally including mild valve abnormalities and small holes between the chambers of the heart. There are also some heart defects that are not evident until after the baby is born.
Few congenital abnormalities can be missed even with best of ultrasound equipment, even in hands of highly experienced and well trained professionals
What happens after the examination?
You would usually receive the printed report on the same day. You can take appointment for any subsequent scans which would then be arranged at the correct time.
A word from Fetal Experts Lucknow
Undergoing any type of prenatal test is nerve-racking. You may be feeling anxious about the thought of undergoing a fetal echocardiogram. Know that this is normal, and you are not alone. Don’t hesitate to ask questions during the exam and once the results are ready.