Though the exact aetiology of ABDC is unknown, two main pathogenetic mechanisms are proposed. Exogenous theory suggests early amnion rupture leading to a fibrous band that can entrap fetal body part (). The endogenous theory suggests vascular compromise.4
Genetic factors might operate in some cases.5
Diagrammatic representation of amniotic bands.
Moerman et al
described three types of lesions in this complex: (A) constrictive tissue bands (shrivelled amniotic strands), (B) amniotic adhesions (fusion between disrupted body part and intact amniotic membrane) and (C) limb–body wall complex.6
According to their observations, most of the craniofacial defects occur as a result of a vascular disruption sequence with or without cephaloamniotic adhesions, unlike the case described here that had the clear mark of a constriction band without significant vascular compromise.
An accurate diagnosis may be achieved by looking for the major features of amniotic band syndrome, and a routine chromosome study and placental examination in cases with multiple congenital anomalies.2 7
Though encephalocele, clefts, distortion and dislocation of craniofacial structures have been described as presentations of craniofacial defect related to this syndrome in the medical literature,5
distorted hemicranium (mimicking caput succedaneum) without any neurological defect has never been described previously. The outcome of the syndrome depends on the gravity of malformation. Termination of pregnancy is considered in cases of severe craniofacial or visceral abnormality. Successful limb salvage by fetoscopic release of an amniotic band has been reported.8
Most of the minor craniofacial defects require multiple surgical procedures to restore function, with significant compromise to satisfactory cosmesis.
- Isolated calvarial deformity mimicking caput succedenum from amniotic band disruption is a possibility.
- Careful neurological assessment and MRI are useful to exclude any neurological abnormality.
- Masterly inactivity with regular follow-up is appropriate management in such cases.