Head circumference below two standard deviations below mean for a given age and gender (≤ 5th percentile).
Causes
-
Primary:
- Trisomies:
- Down Syndrome (Trisomy 21)
- Patau (13) and Edward (18) Syndromes
- Syndromes
- Example: Cornelia de Lange Syndrome
- Trisomies:
-
Secondary:
- TORCH
- Traumatic brain Injury
- Post natal infections
- Alcohol (Fetal Alcohol Syndrome)