How many years in jail for illegal pregnancy in KSA?

There is no written law that organizes the punishment for adultery except from Sharia which determines to lash the adulters 80 lashes if they committed adultery and they are not married to each other.

In addition to this punishment, the judge has the authority to determine the proper punishment per act, and he takes the religion of the defendant into his consideration to decide whether to apply Sharia punishment or not.