Umbilical cord
From Tardis Wiki, the free Doctor Who reference
The baby of Sarah Thomas was born with an umbilical cord. When Ianto Jones asked Jack Harkness what they should do with the cord and the placenta, Jack replied that he'd handle it, stating that he'd delivered babies before. (PROSE: Bay of the Dead)
Gifftan babies were born with two umbilical cords. (TV: The Tsuranga Conundrum)
