The story: I own a horse ranch. I breed horses, and I probably get a little bit too attached. I have a beautiful mare named Rosie, who was pregnant with a foal from one of my favorite stallions I've ever met. I even have a full brother of the little foal that was in utero, and he is amazing. Just 30 days out from the due date, Rosie contracted an infection in her uterusplacenta (called placentitis). Sometimes there are signs beforehand, but she never showed.
Long story short: She lost the foal just 30 days out. A full inspection of the fetus shows it was a little colt in perfect health, except for the placental infection.