Diagnosing and treating a heart problem before birth: A Reality today

Congenital heart disease (heart diseases from birth) accounts for approximately 50% of all deaths attributed to lethal malformations in unborn child.  The incidence in children after birth ranges from 3-8/1000 live births.

With increasing advancement in the field of science it is now possible to detect the cardiac diseases in the fetus (when child is within the mother) with remarkable accuracy and also offer treatment to many of the critical heart

The exam Fetal echocardiography uses sound waves that “echo” off the structures of the fetus’s heart. A ultrasound machine analyzes these sound waves and creates a picture (echocardiogram) of their heart’s interior. This image provides information on how baby’s heart is formed and whether it’s working properly.

It also enables physician to see the blood flow through the fetus’s heart. This in-depth look allows your doctor to find any abnormalities in the baby’s blood flow or heartbeat sessions within the mother’s womb.

The test is extremely safe as is any ultrasound of the body , that’s routinely done in pregnant females. There is no radiation in the test.

Why a specific fetal echocardiography?

When a routine ultrasound is performed during pregnancy, a four-chamber view of fetal heart is routinely performed. However, a four-chamber view of fetal heart may not reliably detect conotruncal abnormalities. Most of the studies have retrospectively evaluated the accuracy of four-chamber view for the diagnosis of congenital heart disease. Sensitivities of between 10-20% reported in prospective studies of the four-chamber view indicate that all patients with any risk factor for congenital heart disease should be referred for detailed fetal echocardiographic study.

Once heart disease is diagnosed one can better manage pregnancy and prepare for delivery.

Results from this test will help plan treatment that baby may need after delivery, such as correctional surgery. One can also get support and counseling to help make good decisions during the remainder of pregnancy.

Fetal echocardiography or ultrasound examination of fetal heart recommendations include:

Indications for fetal echocardiogram:

• Abnormal appearing heart on general fetal ultrasound
• Fetal tachycardia, bradycardia, or persistent irregular rhythm on clinical or screening ultrasound examination
• Maternal or family risk factors for cardiovascular disease, such as parent sibling, or first relative with congenital heart disease
• Family history of heart disease or heart disease in the previous child
• Maternal diabetes mellitus
• Connective tissue disorder in the mother such as Maternal Systemic lupus erythematous
• Teratogen/ Drugs exposure during pregnancy such as medicines for seizure disorder etc
• Other fetal organ system anomalies detected in fetus (including chromosomal)
• Other medical conditions, like rubella, type 1 diabetes, lupus, or phenylketonuria are present
• Performance of transplacental therapy
• Presence of a history of significant but intermittent arrhythmia ( heart rate changes in the fetus). Re-evaluation, examinations are required in these conditions
• Fetal distress or ventricular dysfunction of unclear etiology
• Possible indications for fetal echocardiogram
• Previous history of multiple fetal losses

When to do fetal echocardiogram:

Fetal echocardiogram is  ideally done at 18-24 weeks of gestation. This timing also allows for repeat examination when first examination is incomplete before 24 weeks (maximum time limit of termination of pregnancy in India).

Serial examinations are recommended if diagnosis of cardiac defect is made and pregnancy is continued. Fetal echocardiography has been reported to have high accuracy when performed by experienced individuals. It is an extremely safe test with no radiation involved.

With increasing advancement in scientific technology , there is now the capability to not only diagnose the illness within the womb but also timely treat certain critical illness like narrowing of valve : aortic and pulmonary, within the womb of the mother. These lesions if detected and treated in time prevent the progression of fetus to hypoplastic left heart or hypoplastic right heart syndrome (both with very poor long term outcome. Other cardiac diseases which can be treated in utero include restricted PFO and intractable fetal arrhythmias. It is important to recognize these lesions timely so that appropriate therapy if timely instituted within the mothers womb leads to delivery of a healthy baby.

No specific preparations are needed for the test and can be done even after meals.