Hydrocephalus is a condition characterized by the accumulation of cerebrospinal fluid (CSF) within the ventricles of the brain, leading to an enlargement of the head and potentially causing various neurological issues. Hydrocephalus can be present at birth (congenital) or develop later in life (acquired). The congenital form is more common in infants for several reasons:

1. Developmental Factors: The brain undergoes rapid growth and development during fetal and early postnatal stages. During this period, any disruption in the formation of the ventricular system or the circulation of CSF can lead to hydrocephalus. Congenital hydrocephalus often results from abnormal development of the brain’s ventricles and their connections.
2. Neural Tube Defects: Neural tube defects are congenital conditions that involve incomplete closure of the neural tube, which eventually develops into the brain and spinal cord. These defects can disrupt the normal flow of CSF and lead to hydrocephalus.
3. Genetic Factors: Some cases of congenital hydrocephalus are linked to genetic factors. Certain genetic mutations or conditions can affect the development of brain structures responsible for CSF circulation and absorption.
4. Infections and Maternal Health: Infections during pregnancy, such as rubella (German measles) or toxoplasmosis, can increase the risk of congenital hydrocephalus. Maternal health and exposure to certain toxins can influence fetal brain development and increase the likelihood of hydrocephalus.
5. Intrauterine Hemorrhage: Bleeding within the brain’s ventricles during fetal development can disrupt CSF circulation and lead to hydrocephalus.
6. Chromosomal Abnormalities: Conditions like Down syndrome and other chromosomal abnormalities are associated with a higher risk of congenital hydrocephalus.
7. Early Diagnosis: Congenital hydrocephalus is often detected shortly after birth due to the rapid enlargement of the infant’s head. This early detection allows for timely medical intervention.

While congenital hydrocephalus is more common in infants, hydrocephalus can also develop later in life due to factors such as head injuries, tumors, infections, and other medical conditions that affect CSF circulation and absorption.