Pathologic aspects of the umbilical cord after percutaneous umbilical blood sampling.

Percutaneous umbilical blood sampling (cordocentesis) appears to be a valuable new procedure for prenatal diagnosis. In order to evaluate whether focal injury of the umbilical vessels caused by the needle puncture is potentially harmful, we completely examined 50 umbilical cords collected between 1 hour and 20 weeks after cordocentesis. Macroscopic evidence of the needle entry was found in 37 cases, including one giant hematoma of the cord. Within 48 hours after the procedure, microscopic examination of transverse sections taken at the puncture site revealed distinct perforation of the vessel wall, associated in four cases with a small hematoma encircling the vessel. One week after cordocentesis, the vessel wall was partially reformed. There were no histologic differences between needle entry in a vein or in an artery. No thromboses of the umbilical vessels were found.