A birth defect (or congenital disorder) is a defect in a baby at birth, or which develop in the first month of life.
It is neutral as to whether the cause is genetic (inherited birth defect) or environmental (causes in the environment, that is, outside the foetus).

If a condition is said to be "congenital", that is neutral language.
Often it is not known what causes a condition found at birth.
In common use, it is often redirected to "birth defect".
That term is also neutral as to cause.

There are two main types of congenital defect.
The first is caused by genetic abnormalities, which are hereditary.
The second may be caused by conditions (such as infectious diseases) which a baby may get.
However, we may not know what caused the condition.

Sometimes doctors may find out that a baby has a congenital disorder before its birth.
They use prenatal diagnosis and screening tests, such as amniocentesis.
A birth defect (or congenital disorder) is a defect in a baby at birth, or which develop in the first month of life. It is neutral as to whether the cause is genetic (inherited birth defect) or environmental (causes in the environment, that is, outside the foetus). 
If a condition is said to be "congenital", that is neutral language. Often it is not known what causes a condition found at birth. In common use, it is often redirected to "birth defect". That term is also neutral as to cause. 
There are two main types of congenital defect. The first is caused by genetic abnormalities, which are hereditary. The second may be caused by conditions (such as infectious diseases) which a baby may get. However, we may not know what caused the condition.
Sometimes doctors may find out that a baby has a congenital disorder before its birth. They use prenatal diagnosis and screening tests, such as amniocentesis.
Birth defect