Suspected maternal infanticide in a case of hydranencephaly

A medico-legal autopsy case of hydranencephaly in a male infant which was first suspected of maternal infanticide is reported. The infant was 48 cm in height, weighed 2.86 kg and the circumference of the head, the chest and the abdomen was 32.2 cm, 31.0 cm and 30.4 cm, respectively, with no deformities of the head or body. Autopsy examination, however, revealed a severe defect in the central nervous system. The cranial cavity was filled with a cloudy dark red fluid (ca. 310 ml) instead of the cerebral hemispheres. The residual central nervous tissues were mostly subtentorial structures from the midbrain to the spinal cord namely, corpus mamillare, corpora quadrigemina, corpus pineale, crus cerebri, pons, cerebellum, medulla oblongata and spinal cord. The basal ganglia, thalamus, hypothalamus and chiasma opticum could not be found, although atrophic hypophysis, eyeballs and optic nerves were present. The usual distribution of cerebral blood vessels, especially the branches of the anterior and middle cerebral arteries and Willis' ring, was absent despite the presence of the internal and external carotid arteries. Other organs were, in general, congestive. The marked cortical atrophy of the adrenal glands (left 0.5 g, right 0.6 g), especially the zona fasciculata, was characteristic. The hydrostatic lung test gave partially positive results, but this was considered to be due to artificial respiration by an ambulance man because amniotic fluid components were microscopically noted and fully expanded alveoli were not found. In conclusion, the cause of the infant's death was diagnosed as stillbirth due to aspiration of amniotic fluid caused by the severe defect of vegetative hypothalamic function through hydranencephaly.