This study was conducted to know the definite & probable causes of mental retardation (M.R.) in children & how can we prevent some of the cases. Three hundred eighty three children with moderate to severe (M.R.) were studied in Kerbala Pediatric Hospital over two years from January 2003 to January 2005. The male to female ratio was 1.51:1. The etiology was known in151 patients (39.4%) & was unknown in 232 patients (60.6%). The probable preventable causes include kernicterus, hypoxic ischaemic encephalopathy, severe malnutrition, prematurity neonatal sepsis, hypothyroidism, encephalitis, meningitis, neural tube defect, galactossaemia, shaken baby syndrome & lead poisoning, constituting (68.8%) of the known probable causes. There was a high rate of consanguinity of parents, (37.8%) were first cousin, (24.8%) wer relatives while (37.4%) were not related. Three hundred forty eight patients (90.88%) were diagnosed before their first birthday. It was concluded from the study that we can help to reduce cases of (M.R.) by practicing primary & secondary prevention through health promotion, specific protection; early diagnosis & treatment of treatable disorders by neonatal screening program.
