How many miscarriages can a person have before it is deemed unsafe to get pregnant?

Not unsafe. There is no such thing; just getting pregnant can be unsafe! the bigger problem is the emotional state of the mother. She must be a wreck. Many women have many losses - a work-up is indicated after 3 consecutive losses in the 1st trimester. The good news is that despite the many losses, the chances of a successful pregnancy is still 60-70%.