People who grow up with brothers and/or sisters are all too familiar with sibling rivalries. One sibling always seems to be competing for the attention of the parents or playing with the favorite toy. For twins, the rivalry may be even more intense. In fact, a new video making the rounds on the Web suggests that the twin rivalry may begin even before birth.
The video from CBS News was taken during a "cinematic-MRI" for a study at London's Center for Fetal Care. It shows unborn twins seemingly struggling for space in their mother's womb, with one fetus nudging and kicking the other.
The cinematic-MRI machines were being studied to determine whether they could be used to diagnose twin-to-twin transfusion syndrome, a potentially deadly condition that occurs when blood moves from one fetus to the other. The sudden shift of blood can cause a hemorrhage or stroke in one or both twins. The newly popular video is reminiscent of another recent one, which showed what human birth looks like from the inside.
You'll have to judge for yourself whether the twins are actually fighting or just shifting around to get into a more comfortable position and only bumping into one another coincidentally.