Always keep in mind that sometimes pups will die in spite of your best efforts. Warming box, tube feedings, hydration, oxygen and trips to your vet.
Sometimes puppies get sick in the middle of the night or week ends and I hope the following information will help save your puppy(or puppies) till you can get them to your vet.
Some breeders feel it is better to let nature take its course and allow the puppy to die that the puppy geneically infoerior or just a sick puppy.
I don't think this way. Some puppies due to their placement in the womb may have a disadvantage. The puppies placenta may have tore away right before birth which would cause the puppy needing oxygen at birth. Many other factors can cause a puppy to fade at birth that do not have anything to do with genetics. Like if the lungs were filled with excessive fluids, you would have to work extra hard to save the puppy.
Before your litter of pups come, read and read, talk with your vet and other breeders and read and read. The more you know the better odds your puppies will have to grow up to healthy and happy dogs. Have your warming box and supplies ready before the birth of puppies.