Mira Sorvino
Jeff Kravitz/FilmMagic
"We are overjoyed at the thought of welcoming a new addition to the family," they say in a statement. "With each child the love in our hearts has expanded beyond what we ever imagined was possible."
Sorvino, 41, and Backus are also parents to Mattea, 4, and Johnny, 2.
Sorvino, who won an Academy Award for Mighty Aphrodite, recently appeared in the NBC miniseries The Last Templar, and Backus will next be seen in ABC's Life On Mars.
• Reporting by JULIE JORDAN
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