Amelia refers to a skeletal dysplasia characterized by the complete agenesis of an upper or lower extremity or all four limbs. It may be associated with other congenital anomalies, i.e. omphalocele and diaphragmatic hernias 3.
Amelia is a very rare congenital anomaly with an incidence rate of 0.04-0.15 per 10000 live births 1.
Such type of limb anomalies are associated with 4:
The arrest in the formation of primordial limb bud(s) during the early phase (before the 8th week of gestation) of embryogenesis, may be due to some mechanical, vascular insult or teratogenic exposure.
Antenatal ultrasound may be able to diagnose amelia especially after the latter half of the first trimester as a gross absence of one or more limbs with associated other anomalies.
Prognosis and treatment
The prognosis depends upon the severity of other associated anomalies. More than 60% of newborns die early postnatally due to complicated amelia 2.
Imaging differential considerations include 2:
- 1. Froster-Iskenius UG, Baird PA. Amelia: incidence and associated defects in a large population. Teratology. 1990;41 (1): 23-31. doi:10.1002/tera.1420410104 - Pubmed citation
- 2. Nyberg DA, McGahan JP, Pretorius DH et-al. Diagnostic Imaging of Fetal Anomalies. LWW. (2003) ISBN:0781732115. Read it at Google Books - Find it at Amazon
- 3. Mastroiacovo P, Källén B, Knudsen LB et-al. Absence of limbs and gross body wall defects: an epidemiological study of related rare malformation conditions. Teratology. 1992;46 (5): 455-64. doi:10.1002/tera.1420460510 - Pubmed citation
- 4. Froster-Iskenius UG, Baird PA. Amelia: incidence and associated defects in a large population. Teratology. 1990;41 (1): 23-31. doi:10.1002/tera.1420410104 - Pubmed citation