Answer:
A congenital heart defect (CHD) is a heart problem that a baby has at birth. It is caused by abnormal formation of the heart during growth in the womb. In most cases, when a baby is born with a congenital heart defect, there is no known reason for it. Some types of congenital heart defects can be linked to an abnormality in the number of a baby’s chromosomes. They may be linked to single gene defects. Or they may be linked to environmental factors. In most cases, there is no clear cause that can be found for the heart defect. They are often thought to be caused by many factors. The factors are usually both genes and the environment. This means that genes from both parents plus unknown environmental factors lead to the problem.
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