In this fascinating video, you’ll see twins literally fighting in the womb – the smaller fetus (right) can be seen apparently kicking and punching the bigger sibling as if trying to create more space. Continue reading for the video and more information.

This video was captured at about 20-weeks into the pregnancy and taken as part of a project to monitor a rare condition called twin to twin transfusion syndrome (TTTS); fetuses with the condition share the same placenta, and therefore also the same blood supply.