Umbilical cord from the offspring. The cord along with the placenta is often eaten by the mother, to provide nourishment and to dispose of tissues that would otherwise attract scavengers or predators. In chimpanzees, the mother leaves the cord in place and nurses her young with the cord and placenta attached until the cord dries out and separates naturally, within a day of birth, at which time the cord is discarded. (This was first documented by zoologists in the wild in 1974.) Some species of shark — hammerheads, requiems and smooth-hounds — are viviparous and have an umbilical cord attached to their
Percutaneous umbilical cord blood sampling preexisting defects and abnormalities. While ultrasounds and color flow mapping can be used to avoid the umbilical artery and sample from the umbilical vein, the dilation makes the single umbilical artery easier to puncture. Blood flow in the umbilical artery is seen to be twice the normal amount from about 20 weeks on so the effects of a punctured umbilical artery during PUBS are more severe. Percutaneous umbilical cord blood sampling "For other uses see PUBS ( page)" Percutaneous umbilical cord blood sampling (PUBS), also called cordocentesis, fetal blood sampling, or umbilical vein sampling is a diagnostic genetic test that