Collapsed Uterus???

[GrubaughSG]

This past winter I had a gilt that we lost. She went into labor and started pushing but nothing happened. We tried pulling pigs. He pelvis was plenty big. I have fairly beefy hands and could get my hand through her pelvic bone as could my larger friend. He has experience puling pigs and says that it didn't feel right. We had to fight what felt like large clumps of muscle to even feel any of the babies after we got past the pelvic bone. We managed to get 2 of them out. My best guess is she had a collapsed uterus but i have no idea. Does anybody know what happened or what caused this? Also there is a gilt out of her who is looking very nice and i would like to keep back but would this be a hereditary trait that could be passed on to her? The sow that produce my gilt that died was out was a great mother. 10-12 pigs every time no problems? Could it have came from the boar?