Married in Pregnancy

A man and a woman has committed adultery. Then they repented and want to get married when the time the woman was pregnant. Is the marriage valid?

Their marriage was valid, but they are still sinners for committing adultery. A person who commits adultery shall be punished with 100 lashes if still unmarried when committing adultery. If they are married they should be stoned.
Her unborn baby was the result of his adultery.

Al Ustaz ,Issue 6.