Overweight and miscarriages?

Well, it is because already your heart has to work that much harder to pump blood through your body because you are overweight. When you are pregnant your uterus gets most of the blood flow from your heart because it is feeding the baby its nutriants and it is the baby's life support. When you are pregnant, naturally your heart is going to beat faster, that is normal because it has to supply much more blood to the uterus for the baby to survive. However when you are obese your heart will already be beating faster because it has to pump to all the "fat" as well, if your heart beats too fast it can cause a lot of damage to you and can possible result in death, therefore your body is going to naturally cut the blood supply to save you, and then if the blood is not getting to the baby, the baby cannot survive and the pregnancy will cease. And depending on where all your "fat" is, if it is in the abdomen it puts that much more pressure and weight on the uterus, which is not good either.