Abstract :
Introduction: A cross sectional study was conducted to observe morphological and developmental changes
occurring in thymus gland at various gestational age among human fetuses. The morphometric measurements of
thymus is useful in calculating size as intrauterine growth retardation (IUGR) and cellular immune deficiency of
infant is associated with a significant decrease in fetal thymic size.
Materials & Methods: This study was carried on medically aborted and stillborn fetuses (n=31; F=21, M=10),
which were obtained from Dr. Sushila Tiwari Memorial Hospital, Haldwani, (Uttarakhand,) with due consent of
parents. Fetuses were preserved in 10% formalin. Thymic gland was dissected out to observe its weight, length
and thickness.
Results: Thymus glands were located in superior mediastinum. On gross examination, they were of greyish pink
to greyish brown in colour. Most of the glands were bilobed and few were irregular in shape. There was
progressive increase in all morphometric dimensions of thymus in relation to gestational age. Growth of right lobe
of thymus was comparatively more than of left lobe.
Conclusion: Thymic morphometric parameters in relation to gestational age can be used as reference values in
imaging studies in the prenatal and in initial perinatal stages, so we could compare the normal morphology with
that of in IUGR and immune deficiency.
Keyword :
Fetal thymus gland, morphology, development.