An abruption can happen for any number of reasons but for the most part they just don't really know why. I also have an abruption so I've done quite a bit of researching about this. Your baby can survive as long as there is more than 50% of the placenta that has not torn. You probably already know that your baby gets all his/her nutrients and oxygen through your placenta but it is also how the baby transfers his/her waste, carbon dioxide, etc through to you because the baby is not really capable of disposing or cleansing this stuff up so it is passed back to you for your body to take care of. They can measure how bad the abruption is through an ultrasound. If it is just a small "tear" then they might put you on bed rest if you are bleeding from it. Sometimes these smaller tears will actually clot over and kind of seal themselves off which is great and just means that the doc will monitor it closely to make sure it doesn't get worse. If you have a more severe abruption, you doc would put you in bed for sure and maybe even in the hospital. There isn't really anything they can do to fix an abruption. The only thing they can really do is watch it closely and watch your baby's growth rate and if the tear gets too bad or your baby starts to lag in his/her growth they would consider an early delivery. You do want to take your temperature a few times a day (I do it 4 times per day) and watch for any signs of fever because although it's not really super commen, come women can develop an infection where there abruption and and that can make them toxic and in some cases, it isn't discovered until too late. So, if you have a fever (even a low grade one) you might want to contact your doctor so they can check it out. Oh and your doctor might refer you to a specialist depending on how bad the abruption is because it does put you at a higher risk than a normal pregnancy. So, now that I've totally freaked you out (sorry but if you are like me, you'd rather have all the facts), if your doctor isn't acting overly concerned then you ahould take a few deap breaths and calm down... it's probably not a big tear and just something to watch and keep an eye on. It's better that they found it now than later. On the plus side, you will probably get to see your little one more often :)
if that has happened a doctor should def know what is going on
A placental abruption is when the placenta starts to tear from the uterine wall. It can cause a lot of issues with the unborn child, including death, as the baby recieves his blood and oxygen from the placenta.
A placental abruption can be minor, with a small tear, or it can be a complete placental abruption, where the whole placenta tears from the uterine wall.
I hope this helped out a little bit, and the docs should have known what was going on, although this condition cannot be seen unless an ultrasound is done.