Iniencephaly and Anencephaly with Spinal Retroflexion: A Comparative Study of Twelve Human Specimens

Objective: To study the degree of retroflexion of the cervical spine and the congenital malformations present in cases of iniencephaly and anencephaly. Methods: Twelve stillborn fetuses were examined. Those with anencephaly are prefixed by AN and serially numbered from 1 to 8, and those with iniencephaly are prefixed by IN and serially numbered from I to 4. The specimens were fixed in 25% formaldehyde. Anteroposterior and lateral plain x-ray of the whole body were taken four weeks after fixation. Necropsies were performed and the anomalies observed were recorded and photographed. Results: According to the length of the neck and the direction of the face, retroflexion of the cervical spine was classified into severe, moderate and mild forms. Retroflexion was severe in 2 cases (INI, IN2), moderate in one (IN3) and mild in eight (lN4, ANl-4). The associated malformations affected most organs systems and comprised left diaphragmatic hernia in six cases, broad base of the nose in nine specimens, absent left kidney and hypoplastic lungs in two cases; Fallots tetralogy and patent foramen ovale in one case each. Conclusion: The presence of cervical retroflexion and numerous similar congenital malformations justify a comparative study on twelve cases of iniencephaly and anencephaly. The appearance of the cranial cavity and the brain and the frequent occurrence of caudal myelocele in iniencephaly suggests a different time of onset of these two classes of malformation. This largely reflects the closure ofthe ends ofthe neural tube at different times.