Miscarriage is the most commonly used term for a pregnancy that ends on its own during the first 20 weeks. Between 10 and 25% of pregnancies end in miscarriage making it the most common pregnancy loss.
There are many factors which can contribute to miscarriage including the mother's age (risk increases as mothers age), hormonal issues, improper egg implantation, truama to the mother, and lifestyle. However, some miscarriages take place for no discernable reason.
Most miscarriages take place within the first 13 weekes of pregnancy.