A remarkable new video shows that for twins, sibling rivalry may start even before they are born.

Using the so-called cinematic-MRI scan technology, researchers at London's Center for Fetal Care managed to capture footage of what appears to be unborn identical twins kicking each other and fighting for space inside their mother's womb.

"What this lets us do is see their positions in relation to each other and how much space they occupy, and how they might move around and push each other out of the way," Researcher Dr. Marisa Taylor-Clarke of the Robert Steiner MR Unit at Imperial College London, who recorded the images, said, according to Reuters.

Researchers said that using the cinematic-MRI, which produces more detailed images than conventional MRIs, they were able to capture the remarkable images of what looks like unborn twins fighting for space in the mother's womb.

The images of the fighting twins came from a study that wanted to see whether magnetic resonance imaging technology could be used to diagnose a twin-to-twin transfusion syndrome, according to Reuters.

Twin-to-twin transfusion syndrome is a rare but potentially deadly condition in which blood from one twin moves into the other. The condition occurs only in identical twins and can significantly reduce the blood supply in the twin that loses blood.

The condition can lead the twin that loses blood, or the "donor" twin to being born smaller than the other twin, and usually with paleness, anemia and dehydration, according to the U.S. National Institutes of Health. While the twin that receives the blood is born larger, the recipient twin is usually born with redness, too much blood and increased blood pressure. Experts said that because of the increased blood volume, the recipient twin is significantly more likely to develop heart failure that may require medication to treat.

"We use MRI in twin-to-twin transfusion syndrome, not so much for diagnosing it, which can effectively be done on ultrasound but more for looking at the consequences of it," Taylor-Clarke explained.

"So one of the problems with the imbalances of blood flow is that if you get a sudden shift of blood from one twin to the other, that can cause brain injury, so it can cause stroke or hemorrhage in one or both of the twins' brains. MRI can pick up signs of brain injury much earlier and in much greater detail than ultrasound can at the moment," she said.

For twins who suffer TTS, laser surgery can be done to interrupt the flow of blood from one twin to the other. The procedure allows the fluid imbalance to correct itself. Experts say that after birth, if the condition is mild, full recovery is expected for both twins. However, severe cases may result in death.