Yes there are subs who have been sexual abused (SA) that are in the lifestyle as there are predators (realize I called them predators) who want to exploit those who are sexual abused. It is especially essential that SA subs to be very careful who they choose to be their dominant. Not every person is safe and getting the wrong dominant could really cause some real damage. Subs should know themselves and always have a safety plan for getting in a relationship and getting out.
And if you are choosing partners with a history of this, then that's on you. Some characteristic of abused people attracts you or you wouldn't be so attracted to these people instead of those without such a history.