mental retardation causes

What causes mental retardation? mental retardation causes
Mental retardation occurs because the brain is not developing properly. The development of the brain can be affected by many factors. The causes of mental retardation include:
• problems before the child is born, including poor nutrition for the mother, excess alcohol consumption by the mother and certain types of infections in the mother (in some parts of the world where there are low levels of iodine in the salt, the child may be born with a condition of low thyroid hormone function and mental retardation);
• problems during childbirth, such as prolonged labour or the umbilical cord becoming trapped around the baby’s neck;
• problems in the first year of life, such as infections of the brain, severe and prolonged jaundice,
uncontrolled convulsions, accidents and severe malnutrition;
• problems in the way the child is being looked after, such as poor stimulation, child abuse and emotional neglect;
• genetic conditions, such as Down’s syndrome.
In most children with MR, we can never find out the exact cause.