11. Each villus has a network of capillaries and fine lymphatic vessels called lacteals close to its surface. 12. Villus capillaries collect amino acids and simple sugars taken up by the villi into the blood stream.13. Older women often have amniocentesis or chorionic villus sampling _ invasive tests that give much more definitive answers. 14. Chorionic villus DNA analysis or analysis of fetal red cells can be used to detect TPI in antenatal diagnosis. 15. Once pregnant, testing can be done on fetal cells obtained via chorionic villus sampling ( CVS ) or amniocentesis. 16. The test is chorionic villus sampling, or CVS, which is done at 10 weeks of pregnancy or later. 17. Couples who become pregnant are advised to have amniocentesis or chorionic villus sampling, the current prenatal tests, as backup. 18. These tests can also be performed prenatally to detect aneuploidy in a pregnancy, through either amniocentesis or chorionic villus sampling. 19. The test is for diagnosis, and does not have nearly the same predictive power of amniocentesis or chorionic villus sampling. 20. Microvilli are present on the epithelium of a villus and further increase the surface area over which absorption can take place.
