Laurent will deliver their second child early this summer. "All is going well and they are due in June," says rep Karen Samfilippo.
The new arrival will join big sister Lola Jolie, 20 months. The couple, both 39, wed in New Orleans in 2006.
Thomas, who is best known for his role opposite Julia Stiles in Save the Last Dance, recently appeared on the FOX series Lie to Me as a Secret Service agent.
Reporting by JULIE JORDAN