%0 Journal Article %T La vellosidad placentaria en la malformaci¨®n de Chiari tipo II %A Castej¨®n %A Olivar %A Molinaro %A Mar¨ªa %A Quiroz %A Daniel %J Revista de Obstetricia y Ginecolog¨ªa de Venezuela %D 2005 %I Sociedad de Obstetricia y Ginecolog¨ªa de Venezuela %X objective: it is our proposal to evaluate with light microscopic stains a general vision of the placental villous tree with the types of villous structure and maturation associated in a case of chiaris ii£¿s malformation. method: samples of the last branches of the villous tree of placenta grade i, of 24 weeks of gestation were compared with normal villi of the same age. setting: laboratory of electron microscopy, ciadana. results: stem villi with a stromal fibrous core and no completely fibrosed stroma were observed. immature intermediate villi with scarce mature intermediate villi are the dominating villous types. decreased amount of terminal villi are seen in mature intermediate villi. conclusion: these findings indicate a persisting villous immaturity that shows 4 _ weeks of retardation with reference to normal pattern being lightly asynchronous. this blastogenetic malformation originated by defects of the embryonic midline, frequently lethal and multisystemic anomaly involve defects of placentation or cord malformation that tend to be severe and complex producing low fetal weight and fetal death. %K placental villi %K chiari¡äs malformation. %U http://www.scielo.org.ve/scielo.php?script=sci_abstract&pid=S0048-77322005000100005&lng=en&nrm=iso&tlng=en