Proportion of microcephalic infants presenting with other congenital anomalies
| Microcephaly, n (%)* | |
| Central nervous system | |
| Spina bifida | 11 (1.4) |
| Anencephaly/encephalocoele | 12 (1.5) |
| Congenital hydrocephalus | 6 (0.8) |
| Other | 42 (5.3) |
| Any | 65 (8.2) |
| Eye | 20 (2.5) |
| Ear | 17 (2.1) |
| Orofacial clefts | 19 (2.4) |
| Heart | |
| Critical | 20 (2.5) |
| Non-critical | 80 (10.1) |
| Any | 89 (11.2) |
| Respiratory† | <5 (<0.6) |
| Digestive | 23 (2.9) |
| Urinary | |
| Hypospadias | 8 (1.0) |
| Renal agenesis | 6 (0.8) |
| Other | 19 (2.4) |
| Any | 32 (4.0) |
| Skeletal | |
| Congenital hip dislocation | 12 (1.5) |
| Clubfoot | 29 (3.7) |
| Limbs and digits | 13 (1.6) |
| Skull and face bones | 16 (2.0) |
| Other | 24 (3.0) |
| Any | 73 (9.2) |
| Chromosomal | |
| Down | 17 (2.1) |
| Trisomy 13 or 18 | 11 (1.4) |
| Autosomal or sex-linked | 11 (1.4) |
| Other | 10 (1.3) |
| Any | 47 (5.9) |
| Lethal‡ | 50 (6.3) |
| Any defect§ | 295 (37.2) |
| Isolated microcephaly | 499 (62.8) |
| Total | 794 (100) |
*Categories are not mutually exclusive, and microcephalic neonates with two or more other anomalies appear more than once.
↵†Fewer than five defects cannot be reported, to comply with data confidentiality requirements.
‡Potentially lethal defects, including anencephaly, encephalocoele, omphalocoele, diaphragmatic hernia, lung agenesis, critical heart defects, renal agenesis, osteogenesis imperfecta, osteochondroplasia, trisomy 13 and trisomy 18.
§Includes all defects in the table plus the ranges 740–742.0, 742.2–759, Q00–Q01.9 and Q03–Q99 of the International Classification of Diseases.