Still-births of cavies

Question
My female guinea pig kept suffering from failed pregnancies. Her tummy will get really big, and when she delivered, the babies looked perfectly normal, and yet perfectly still. She would step on them and refuse to lick them, a clear indication that there are dead. I have tended to pregnant guineas before, and did not encounter any problems in the past.

However this particular guinea had experienced more than 3 failed pregnancies this year alone. Please advice.

Is it her diet? Cage space? We didn't touch the babies until we are sure they are dead. Thanks!

Answer
The best thing to do is not breed this female again. I have realized now that a majority of the time when a female does not clean off her babies it is because they have something wrong with them, often the mother was inbred. Inbreeding affects a guinea pig line for at least 2 generations, if it can make it through the first. The babies have whats called clef palets, the mother often doen't clean them off at birth, or she does, but fluid gets into their mouth and sufficates them because they have a tiny hole in the upper part of their mouth. I have come to this conclusion because I have had a lot of rescue pigs give birth, and often I personally clean off the babies and handfeed them (the mom will not feed deformed babies) and they always die by the 3rd week, then I would not catch a delivery and the babies would not be cleaned off, so they would die. The best thing to do is not breed her, even if you tried to clean off the babies, they will likely not survive, guinea pig moms usually do things like this for a reason. Let me know if you have any more questions.
Brittany