At work, of course, talking about how to pronounce various Latin-derived words (including amicus, some in the ah-mi'-cus camp, while I am in the aym'-i-cus camp) we started talking about "uteruses" versus "uteri". One of the women said it was more or less a moot point, since no one had more than one uterus. First, we may want to refer to more than one person's uterus (the uteri of the women...), and, more interestingly, there are people with more than one uterus.
It's called Didelphys Uterus. It carries risks for pregnancy, although most people who have it don't know about it until they experience fertility problems. It's easy enough to diagnose with an ultrasound, it looks like. Here's a picture that I can't understand, and another one that I also can't understand. And this crazy story about triplets! I wish I was a doctor, not a lawyer (okay, an almost-lawyer).