Hydrocephalus classification according to causes
| Type of cause | n (%) |
| Unknown | 108 (63.9) |
| NTD related only | 35 (20.7) |
| Aqueductal stenosis | 12 (7.1) |
| Aqueductal stenosis+NTD | 5 (3) |
| Dandy-Walker malformation | 4 (2.3) |
| Aqueduct blockage | 5 (3) |
NTD, neural tube defect.