3. Infections and Intoxication

   Certain infections during pregnancy, such as rubella or syphilis, can lead to intellectual disability in the offspring. Exposure to toxins such as alcohol, drugs or tobacco by a pregnant mother can also affect the child.

4. Trauma

   Physical trauma to the mother may result in brain injury to the fetus and can subsequently cause intellectual disability.

5. Malnutrition

   Under-nourishment in the pregnant mother can affect the development of the fetus and lead to intellectual disability in the child.

6. Radiation

   Intellectual disability in the child can be caused by the mother's exposure to nuclear or X-ray radiation.

7. Metabolic Disorders

   Persons with PKU (Phenylketonuria) have a faulty metabolism of the protein phenylalanine resulting in the release of incomplete metabolites that harm the brain. Galactosemia is a defect in the body's ability to break down galactose (a milk by-product), the effects of which are detrimental to the brain.

During Birth

1. Asphyxia

   Prolonged labour can result in a lack of oxygen supply to the baby's brain leading to intellectual disability.

2. Trauma

   Physical injury to the brain during birth can also cause intellectual disability.