When King Felipe of Spain and his wife Queen Letizia welcomed their daughters, Princess Leonor and Infanta Sofia in 2005 and 2007, they made a fascinating decision.
They saved the stem cells from their children's umbilical cords for potential medical use in the future, and it was during his announcement of his second daughter Sofia's birth that King Felipe made the surprising revelation.
He revealed: "We have kept the umbilical cord as with Leonor. It is something in which we have a lot of confidence, and we believe in it. I believe that science and medicine are advancing a lot in this field and we have learned a lot about it."
The Spanish monarch added: "Thanks to the precision of Dr Recansens we have been able to extract enough blood to fill two bags and one will go to the public bank and another to a private bank within Europe."
Leonor's stem cells are stored in a blood bank in Tuscan, Arizona, unlike Sofia's which are stored in Europe.
Storing stem cells
According to the NHS, core blood is the blood that remains in the placenta and umbilical cord after a baby's birth. It's rich in stem cells, the 'building block' cells in the body, which can develop into many different types of cell.
The website says: "Thanks to scientific research in this field, we are constantly discovering more and more diseases and conditions that can be successfully treated with stem cells found within cord blood.
"Stem cells taken from the donated cord blood must match the patient's tissue type as closely as possible to give the best chance of successful treatment."
Storing stem cells from the umbilical cord is becoming a more popular practice, albeit an expensive one.
Kourtney Kardashian is one celebrity who is a proponent of storing cord blood from her baby.
During her hospital stay for the birth of her last baby Rocky, she packed a cord collection blood kit in her hospital bag. "Umbilical cord blood contains tons of stem cells," she noted, recognizing the potential future health benefits.
She also packed a placenta encapsulation kit, explaining: "The placenta is full of nutrients, and ingesting it is thought to help with healing after giving birth."