What percentage of people have miscarriages?

Research shows that 50% of all (including the first 2 weeks when people don't know they are pregnant and never know they were) pregnancies end in miscarriage. That number drops to around 10-25% after the 3rd week. Women in there 20s-30s are around 10-15, while 35+ is about 25%. 80% of all miscarriages happen in the first 12 weeks. After 12 weeks or the first trimester the chance of miscarriage drops to around 1-3% depending on age and health of the mother.

Hope this helps.

More info at the link below.

http://www.webmd.com/infertility-and-reproduction/guide/pregnancy-miscarriage