Umbilical cord blood

I am a Chinese, my husband is British. My due date is 28th this month. In China, doctors suggest couples to save their umbical cord blood, it's kind like they collect your blood while the baby is born and deliver it to official blood bank to save it. I have heard that before, some of my friends did. It's like a insurance if any bad things happens with your baby's stem cells, you can take it out and save the baby's life. We don't know if its usual in the U.S. or Great Britain or other countries. Can you pls give us some suggestions. Thank you.