Role of vermal anteroposterior length and width in age determination of fetus

Background: Early differentiation of the cerebellum during fetal life makes it the center of interest in the field of obstetrics and gynecology. Moreover, the cerebellar vermis develops a little ahead of the hemispheres. Hence, the morphological parameters of the vermis can be a guide to ascertaining gestational age and assessing any anomalies related to posterior cranial fossa development. Aims and Objectives: The study was taken up with the objective of building up a timeline for the appearance of folia and important fissures. Moreover, establishing a correlation between the growing fetus and vermal parameters. Material and Methods: A total of 60 human fetal fixed cerebella were included in this observational and descriptive type of study. Fetuses affected with any congenital or neurological deficit were excluded. Grouping of the fetuses was done, based on their gestational age in weeks. The first group from 13-17 weeks, the second group from 18-22weeks, the third group from 23-27 weeks, and the fourth group from 28-32 weeks. Observation: Time of appearance of folia and fissures were noted. Vernier calipers were used to measure vermal width and anteroposterior length. Statistical tools like IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp. and one-way analysis of variance were applied to the data obtained. Conclusion: A posterolateral fissure appeared at 13 weeks of gestation while folia and other fissures appeared from the 18th week onwards. Both the parameters of vermis showed a linear correlation with gestational age. Such a timeline and correlation shall prove to be helpful in calculating fetal age in the field of forensic studies.