The risk factors for intellectual disability are divided into three categories which are pre-natal, perinatal, and post-natal risk factors.

Prenatal causes ^[1]

1. Genetic syndromes
2. Inborn errors of metabolism
3. Brain malformations
4. Maternal disease
5. Environmental factors such as the history of alcoholism, teratogens, and other drugs

Perinatal causes include events during labor and delivery that ultimately lead to ischemic injury to neonates’ brains. ^[2]

Postnatal causes ^[3]

1. Hypoxic-ischemic injury
2. Traumatic brain injury
3. Infections
4. Demyelinating disorders
5. Infantile spasms
6. Severe and chronic social deprivation
7. Heavy metal poisoning
8. Toxic metabolic syndromes

Risk factors for mental retardation include genetic syndromes, hypoxic ischemic injury, and seizure disorders among others.^[1]

• Genetic syndromes (e.g., sequence variations or copy number variants involving one or more genes; chromosomal disorders)
• Inborn errors of metabolism
• Brain malformations
• Maternal disease (including placental disease)
• Environmental influences (e.g., alcohol, other drugs, toxins, teratogens)
• Variety of labor and delivery-related events leading toneonatal encephalopathy
• Hypoxic ischemic injury
• Traumatic brain injury
• Infections
• Demyelinating disorders
• Seizure disorders (e.g., infantile spasms)
• Severe and chronic social deprivation
• Toxic metabolic syndromes and intoxications(e.g., lead, mercury)^[2]