Apparently, sibling rivalry can start even before kids are born.

In an amazing video caught by a high-tech monitor, known as the cinematic MRI, doctors saw an amazing scene of twins fighting for space in the uterus.

Doctors were using the latest MRI technology to diagnose twin-to-twin transfusion syndrome (TTTS), a condition that causes one twin to absorb and “steal” more blood and nutrients from the other twin.

“A lot of the so-called videos in the womb are very processed, so they do a lot of reconstructing and computer work afterwards. These are the raw images that are acquired immediately,” Dr. Taylor-Clarke explained.

And while this new technology can allow doctors to monitor these sometimes-fatal conditions, it allows some of us to get a quick peek of what can happen inside the womb.