RESUMO
Introduction: Thymus consists of two pyramidal lobes. It is located in the mediastinum behind the sternum andin front of the pericardium and great vessels of the heart. The present study has been undertaken to highlightsome important points in morphometry of foetal thymus gland.Materials and Methods: In the present study 30 foetuses (12-38 week) were studied. The obtained foetuses werefixed in 10% formalin. After proper fixation they were subjected to dissection. The length and breadth of glandwas measured by vernier caliper in centimeters. Weight of the gland was measured using electronic weighingmachine. Naked eye examination done for number of lobes.Results: The average length of the thymus at 12th week was 0.2cm on right side and 0.2cm on left side, it wasincreased to 4cm on right side and 4.5cm on left side. The average breadth of thymus was 0.12cm on right sideand 0.10cm on left side at 12th week which was increased to 2.2cm and 2.6cm on right & left side respectively at38th week. The average weight of thymus was 0.1 gm at 12th week and 8.2 gm at 38th week. The majority of thymus26(86.67%) shows presence of two lobes.Conclusion: All parameters length, breadth and weight of thymus show gradual increase with advancing gestationalage with significant changes. There are wide variations in number of lobes of thymus gland.