I don't know statistically what the chances are but if you have had two miscarriages and you have a good doctor, you should know the reason by now. Unless it is a very early miscarriage there are indicators as to why this is a repeated occurrence. Often times, insufficient Vitamin E will cause miscarriage. Be sure to take your prenatal vitamins before you conceive and research the reasons for miscarriage instead of the statistics of how many times. That is an average and you are an individual.