Ans. (b) Congenital hydrocephalus.* Excessive accumulation of cerebrospinal fluid (0.5-1.5 L) in the ventricles with consequent thinning of the brain tissue and enlargement of the cranium, occurs in 1 in 2000 deliveries.Factors favouring diagnosis of cephalo-pelvic disproportion due to fetal factors(1) The head is felt larger, globular and softer than the normal head.(2) The head is high up and impossible to push down into the pelvis.(3) EHS is situated high up above the umbilicus.(4) X-ray: (a) Cranial shadow is globular rather than normal ovoid (b) Fontanelles and sutures are wide (c) Vault bones thinner.(5) Sonography shows that the lateral and third ventricles are dilated with marked thinning of the cerebral cortex Radiological Anatomy to solve these questions-">