Loeb, 43, is expected to give birth in June, People.com reported Monday.
She and Roey Hershkovitz, music production supervisor for "Conan," married in 2009. They are already the parents of a 2-year-old daughter, Lyla Rose.
"I grew up with a big family, so I'm excited for Lyla to have a sibling!" Loeb told People.com.