title: Studies on the ultrastructure of the term amnion in pathological pregnancy.
abstract: The ultrastructure of the amniotic epithelium at term was examined in cases of intrauterine growth retardation of the fetus and compared with amnions obtained from women with a clinically unremarkable pregnancy. In uterine growth retardation the amniotic cells exhibit a general deficiency of a series of functionally significant cell organelles. The RER is insufficiently developed, there is a diminution of the normally numerous free ribosomes as well as of those cell organelles which are involved in secretory function. A further atypical finding is the common lack of intercellular canals playing an important role in the transamniotic exchange of material. Besides this, a very poor development or a complete disintegration of the microfilamentous cytoskelet is generally noticed. The present findings give once again evidence for a very close relation between the structural appearance of the intercellular diffusion canals and the microfilamentous system. The results presented are suggestive of an amnion which is in a state of reduced secretory activity, additionally, due to the common lack of intercellular canals an inhibition of the interepithelial passage between the maternal and amniotic compartment cannot be excluded.
mesh_terms: D000650:Amnion / Q000648:ultrastructure*; D002462:Cell Membrane / Q000648:ultrastructure; D003599:Cytoskeleton / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005260:Female; D005317:Fetal Growth Retardation / Q000473:pathology*; D005865:Gestational Age; D006056:Golgi Apparatus / Q000648:ultrastructure; D006801:Humans; D008871:Microvilli / Q000648:ultrastructure; D008928:Mitochondria / Q000648:ultrastructure; D009940:Organoids / Q000648:ultrastructure; D011247:Pregnancy