Think you come from a big family? Think again.

A woman whose son was conceived using donated sperm has learned the same donor has fathered at least 150 other children, with more yet to be counted.

The situation is alarming to parents, donors and medical experts, but unlike other countries such as Britain, France, and Sweden, the United States doesn’t limit how many times the same donor’s sperm can be used.

George Washington University Law Professor Naomi R. Kahn said without such limitations, one man could potentially father countless offspring, leading to the possibility of accidental incest when those kids grow up.

[via UPI]