Measurement of Filum Terminale in the Foetuses of Third Trimester Gestational Age: An Observational Study

Abstract

Introduction: The covering of spinal cord is same as that of brain. The pia mater, arachnoid and dura mater covers the spinal cord from inside out. The pia mater extends from cephalic end of spinal cord upto terminal portion i.e., conus medullaris. Beyond the conus, the pia mater extends in the form of filum terminale. The filum terminale extends beyond the conus medullaris and attaches upto dorsal aspects of coccyx to stabilise the spinal cord in its position. Aim: To study the length of filum terminale in the foetuses of third trimester gestational age. Materials and Methods: The present cross-sectional observational study was carried out in 30 foetuses collected from museum of Department of Anatomy and Department of Obstetrics and Gynaecology. The permission and approval from university ethical committee was taken before starting the study. The foetuses were divided into three groups taking into consideration their gestational age (four foetuses in 1st group 28- 31 weeks, 12 foetuses in 2nd group 32-35 weeks and 14 foetuses were in 3rd group 36-40 weeks gestational age). Also, the gender wise variation (11 male and 19 female foetuses) was also taken into account. All the data were recorded in Microsoft excel sheet and Statistical Package for the Social Sciences (SPSS) 23.0 software was used for statistical analysis. Numerical values were reported as the mean±standard deviation. Student’s t-test or one way ANOVA was used to analyse quantitative variables. Two tailed p-values were considered significant (p<0.05). Results: In this study, the mean length of filum terminale was 4.35±1.04 cm with range minimum 2.31 cm to maximum 5.90 cm. The length of spinal cord and length of filum terminale measurements significantly increased with increasing gestational age (p<0.001). The length of spinal cord, length of filum terminale measurement and ratio of length of filum terminale to length of spinal cord (FT/SC) were significantly higher in male foetuses (p<0.05). Conclusion: The association between gestational age (weeks), length of filum terminale, and length of spinal cord among all foetuses, and male and female separately were statistically significant