Aims: We delineate and review the central nervous system (CNS) pathology of amniotic rupture sequence (ARS) and its extraneural associations.
Materials and methods: We review a consecutive 15-year fetal/neonatal autopsy series for cases of ARS to document its morphology and correlates.
Results: We retrieved 15 cases of ARS with complete dissection of the CNS. Seven lacked craniofacial abnormalities; in these the brain and spinal cord were normal. Eight had acalvaria or encephalocele, with facial clefts. All 8 had abnormal brains. Two cases demonstrated normal cerebral lobation with aqueductal stenosis/atresia (AS) and secondary changes. Two cases demonstrated holoprosencephaly and AS. Four other cases had large encephaloceles covered by amnion and extensive secondary change, 3 of which had absent olfactory bulbs, folded and thinned cerebral cortex, reduced thalami, and irregular ventricular systems with superimposed gliosis and hemorrhage. In these, the aqueduct or rostral 4th ventricle was either atretic or occluded by heterotopic neuronal masses.
Conclusion: CNS pathology in ARS is strongly associated with craniofacial clefts. There is a non-random association between AS, holoprosencephaly, and ARS. Some of the anomalies may be due to abnormal induction events, vascular instability, and the mechanical effects of craniofacial maldevelopment.