Causes of small head in babies .

Causes of small head in children (Microcephaly )

Causes of microcephaly is related closely to mental retardation , as in mental retardation the brain is not growing well and this leads to small head microcephaly .

A-        Genetic causes

1- Autosomal dominant

2- Autosomal recessive

3- Syndromes like Down Syndrome – Edwards Syndrome – cri du chat syndrome .

B-         Secondary (non genetic causes)

1-Intra uterine infections as infection with cytomegalo virus 

2- Exposure to irradiation in the pregnant mother

1-         Toxins as fetal alcohol syndrome and Fetal hydantoin syndrome

2-         Hypoxic ischemic encephalopathy which is a common cause , when the new delivered baby fail to respond to resuscitation lead decreased oxygen to the brain .

3-         Kernicterus which is damage to the basal ganglia due to high bilirubin level .

4-         Another post natal problem is Intracranial hemorrhage

Meningitis or Encephalitis