Congenital heart defects (CHDs), which are structural abnormalities of the heart present at birth, remain the most common type of birth defect worldwide. Despite remarkable advances in medical science, it is estimated that approximately 8 out of every 1,000 newborns are affected by a congenital heart defect.
These abnormalities can vary widely in severity, ranging from small defects that may resolve spontaneously to complex and life-threatening conditions involving blocked arteries, malformed valves, underdeveloped heart chambers, or abnormalities in the connections between major blood vessels. Many affected infants require one or more cardiac surgeries or catheter-based interventions after birth. For expectant parents, the diagnosis of a serious heart defect can be emotionally overwhelming and difficult.
The fetal heart is a remarkable organ— it starts beating by about the 5th week of pregnancy, at a stage when the embryo is as tiny as a rice grain. Fetal echocardiography is a specialised ultrasound examination that provides detailed images of a baby's heart while still in the womb. This advanced imaging technique evaluates the heart's chambers, valves, major arteries and veins, blood flow patterns, pumping function, and even rhythm disturbances or electrical abnormalities.
The accuracy of fetal echocardiography in detecting major congenital heart defects approaches 98% in experienced hands. The optimal time to perform a fetal echocardiogram is between 20 and 24 weeks of pregnancy, when the fetal heart has developed sufficiently for detailed assessment while still allowing adequate time for decision-making and delivery planning. In selected high-risk pregnancies, an early fetal echocardiogram may be performed between 14 and 16 weeks of gestation.
Like a routine obstetric ultrasound, fetal echocardiography is performed using a transducer placed on the mother's abdomen. High-frequency sound waves are used to create detailed images of the unborn baby's heart. The procedure is safe, non-invasive, painless, and does not involve radiation exposure.
Most expectant mothers are familiar with the routine anomaly scan performed between 18 and 20 weeks of pregnancy. Conducted by radiologists or obstetricians, this important examination evaluates the developing baby's brain, spine, kidneys, limbs, and heart. However, while the anomaly scan includes an assessment of the heart, it is not equivalent to a dedicated fetal echocardiogram.
During a standard anomaly scan, the heart is evaluated using a limited number of screening views and typically receives only a small portion of the overall examination time. In contrast, fetal echocardiography is a comprehensive and focused assessment performed specifically to evaluate cardiac anatomy and function in detail. It means taking a ‘closer look’ by the right experts.
A fetal echocardiogram is best performed and interpreted by a pediatric cardiologist with specialised training in fetal cardiology. Such specialists possess detailed expertise in congenital heart disease and fetal circulation, allowing them to identify subtle cardiac abnormalities that may not be apparent during routine prenatal ultrasound examinations.
When a cardiac abnormality is present, identifying it before birth can be one of the most valuable opportunities modern medicine can offer a family, allowing time for counselling, preparation, and planning of specialised care.
Healthcare providers typically recommend fetal echocardiography for pregnancies considered to be at increased risk of congenital heart disease. These include mothers with pre-existing diabetes, pregnancies conceived through in vitro fertilisation (IVF), fetuses with chromosomal abnormalities such as Down Syndrome, or when other structural anomalies are detected during routine prenatal scans. A family history of congenital heart disease, exposure to certain medications during pregnancy, or abnormal findings on a standard obstetric ultrasound may also warrant a detailed fetal cardiac evaluation.
Though fetal echocardiography test is not mandatory for all pregnant women in India, other countries such as Australia, North America and most of Europe include it as a part of structured prenatal care and tests for all.
Early diagnosis through fetal echocardiography not only improves preparedness but can significantly influence outcomes by ensuring that delivery occurs at a centre equipped to provide specialised neonatal and cardiac care. Science has also advanced to a stage wherein a few heart defects can be addressed in utero via minimally invasive interventions such as ballooning of fetal valves before birth.
While not every congenital heart defect can be prevented, many can be identified before birth, allowing newborns to receive timely, life-saving treatment. In an era where medicine increasingly focuses on prevention and preparedness, taking a closer look at the fetal heart may be one of the most valuable investments in a child's future health.
The author is a consultant pediatric cardiologist at CHC, Kokilaben Dhirubhai Ambani Hospital, Mumbai.
The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.
