Three-Dimensional, Image-Based Evaluation of the L5 Vertebral Body and Its Ossification Center in Human Fetuses

<b>Objectives:</b> The aim of this study was to characterize the developmental trajectories of the fifth lumbar vertebra in human fetuses by assessing the growth of its vertebral body and ossification center using linear, planar, and volumetric measurements. <b>Methods</b>: A total of 54 human fetuses (26 male and 28 female) aged 17-30 weeks of gestation were examined. Computed tomography, digital image analysis, 3D reconstruction, and statistical modeling were used to quantify morphometric parameters of the L5 vertebral body and its ossification center. <b>Results</b>: All measured parameters demonstrated consistent age-related growth following a linear pattern. No statistically significant differences between sexes were observed in any measured diameter of the L5 vertebra or its ossification center within the examined gestational age range. <b>Conclusions</b>: The normative morphometric data and growth curves obtained for the L5 vertebra and its ossification center provide age-specific reference values that may aid in prenatal diagnostics. These findings can support clinicians in estimating gestational age, assessing vertebral development on ultrasound, and detecting congenital spinal anomalies and skeletal dysplasias at an early stage. Further multicenter studies including a broader gestational age range are warranted to strengthen the generalizability and clinical applicability of these results.