Understanding Congenital Heart Defects: Root Causes and Strategies for Prevention

Congenital heart defects (CHDs) are defined as structural disorders that occur at birth, potentially altering the normal blood flow through the heart and significantly contributing to the infant mortality rate. It requires prompt medical attention, as timely diagnosis and treatment are key to ensuring a good outcome. According to a status report on congenital heart defects in India, the birth prevalence of CHD is reported to be 8-12/1000 live births, with an estimated 1.35 million babies born with CHD globally each year. This is a huge number. With limited number of cardiac centers available in the country and too mostly in the private sector, raising money for child surgery becomes another big challenge for many families.

When delving into the root causes of these diseases, it becomes clear that they are multifactorial in nature. Information available through research studies, hospitals and Children Heart Foundation India, reveal several known factors are associated with CHD, including maternal factors.

Some maternal factors increase the risk of the baby being born with a Congenital Heart Defect

Maternal factors:

One major risk factor is advanced maternal age, specifically 40 years or older. Additionally, there is a direct correlation between chronic maternal conditions and CHD. These conditions include:

A. Diabetes:

•  High levels of insulin can interfere with the proper development of the fetus.
• It is important to note that this does not apply to gestational diabetes, which is diagnosed only during pregnancy.

B. Hypertension:

•  High blood pressure in the mother can lead to a condition called pre-eclampsia, which can result in decreased blood supply to the fetus, adversely affecting its growth.

C. Obesity:

Increased maternal BMI is associated with an increased risk of specific heart defects, such as atrial septal defects.

D. Alcohol/smoking/substance abuse:

 The use of such substances can have harmful effects on the developing fetus’s tissues.

E. Use of medication during pregnancy:

• Certain medications, such as anti-seizure medicines like diazepam, acne medications like topical retinoids, and ibuprofen (especially when taken after 30 weeks of pregnancy), can pose risks to the fetus.
• Proper prenatal counseling should be provided to mothers with chronic conditions to help them understand the potential effects on their children.

Intrauterine infections, which can be transmitted from the mother to the child, particularly during the first trimester, can also have a negative impact on fetal development. These infections include:

1. Rubella:

• Rubella can cause heart abnormalities in the fetus, particularly if the mother contracts it between 8-10 weeks of pregnancy. It is also associated with eye and ear abnormalities.

2. Flu (Influenza):

• Women who contract the flu during the first trimester of pregnancy have a higher risk of having a baby with congenital heart disease compared to the general population.

Timely vaccination of the mother during antenatal visits is the most effective preventive measure. The correct dosage and intervals between follow-up doses should be administered for optimal effectiveness. Healthcare providers should inform mothers about the importance of vaccination.

Family history and genetic causes

Family history and genetic causes also play a significant role in CHD. CHDs can be inherited along family lineages, often in autosomal dominant patterns, meaning there is a 50% chance of having the same defect as the parent with each pregnancy. Having a first-degree relative with CHD increases the risk by almost three times.

Chromosomal abnormalities are among the root causes of congenital heart defects.

These abnormalities include:

• Down syndrome: a genetic defect associated with additional disabilities.
• Turner syndrome: primarily affects females and often involves heart valve problems.
• Noonan syndrome: a genetic disorder that can cause a range of symptoms, including pulmonary valve stenosis.

Early diagnosis can be facilitated through fetal echocardiography and chromosomal mapping.

While the causes of congenital heart defects are numerous, with some still unknown, strategies should be implemented to prevent those that can be addressed, thus improving the prevalence of these diseases. Accessible and timely antenatal visits, along with proper care, should be provided to all women during pregnancy. Healthcare professionals should adhere to basic plans for these visits to enable early.

Timely diagnosis and treatment are key to ensure a good prognosis for a child born with a CHD. However, treatment can be very expensive making it out of reach for many families and raising money for child surgery can push many of these families into lifelong debt. As a children heart Foundation India, we support the medical treatment of underprivileged children born with a heart defect to ensure that every child is given a chance to live irrespective of the resources the family has. Every Child Matters.

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