Histogenesis and Histomorphometric study of Human Fetal Small Intestine

BACKGROUND: Intestine plays a major role for the normal growth of the fetus during the prenatal period. The process of the embryonic development is not quantified histologically. Therefore the main aim of the study was to measure the thickness of all part of the wall of the small intestine that are mucosa, submucosa and muscularis externa and to look for the appearance of the Brunner's glands and Peyer's patches in the submucosa of duodenum and ileum. METHODS: The present study was carried out on 30 fetuses of gestational ages ranging from 11–36 weeks. Ten fetuses from each trimester were used in the study. Fetal small intestine were dissected carefully, and were separated as duodenum, jejunum & ileum and fixed in formalin solution. The tissue was processed for histology and then slides were stained with Haematoxylin and Eosin. The microscopic features were noted using light microscope. RESULTS: The thickness of the mucosa, submucosa and the muscularis externa was observed to be increased in first trimester, decreased in the second trimester and again increased in the third trimester, which could be because of the increase cell turnover and the arrangement of the collagen fibers as to support the mucosa and the muscularis externa. CONCLUSION: Thus, the knowledge of the histogenesis and histomorphometry of the human fetal small intestine is crucial for the adult gastroenterologist to appreciate, because of the potential for these early life events to affect the responsiveness of the intestine to physiological or pathological challenges in later life.