When the mother has high blood pressure (hypertension ) or blood poisoning (toxemia), the flow of oxygen to the fetus may be reduced, causing brain damage and mental retardation.
Downs syndrome is caused by having 3 copies, trisomy, of chromosome 21 in your DNA. This can be random, causes are often unknown although it is associated with increased maternal age. Symptoms include characteristic facial features, varying degrees of mental retardation/learning difficulties, a happy and sociable disposition, increased susceptibility to certain heart conditions and other medical conditions and many others. Best to google it for a very quick overview.
down syndrome
Examples of such accidents are development of an extra chromosome 18 (trisomy 18) and Down syndrome.
Isotretinoin can cause serious birth defects, including mental retardation and physical deformities. This medicine should not be used during pregnancy.
If a neurological cause such as brain injury is suspected, the child may be referred to a neurologist or neuropsychologist for testing.
Maternal infections and such illnesses as glandular disorders, rubella, toxoplasmosis, and cytomegalovirus (CMV) infection may cause mental retardation
The two conditions are not at all related. Autism does not cause mental retardation.
Overstudy does not cause mental retardation.
Maternal infection at conception or within the first two weeks of pregnancy may lead to hearing and vision loss and mental retardation.
Maternal infections and illnesses such as glandular disorders, rubella, toxoplasmosis, and cytomegalovirus infection may cause mental retardation.
TThere are quite high as it comes in different types of mental retardation.
Exposure to lead can also cause mental retardation.
literature review on mental retardation with reference
The term "mental retardation" is generally considered outdated and offensive. People with intellectual disabilities may have a shorter life expectancy due to health complications or co-occurring conditions, but it is not accurate to say that a specific number of people die specifically from having an intellectual disability. It is important to focus on providing proper support and healthcare to improve the quality of life and longevity for individuals with intellectual disabilities.
Mental retardation has different levels. There is Mild intellectual disability; moderate intellectual disability; severe intellectual disability; and Profound intellectual disability.https://www.floridahospital.com/mental-retardation-mr/symptoms-and-signs-mental-retardation
because some ppl are born with birth defects like mental retardation
About one-third of individuals with CP have moderate-to-severe mental retardation, one-third have mild mental retardation, and one-third have normal intelligence.