Spelling, who most recently starred on True Tori, has revealed she's pregnant with her fifth child.
"It was a total surprise," Spelling toldPeople. "But we always wanted a big family. I'm really excited."
Spelling and McDermott are already parents to Liam, 9, Stella, 8, Hattie, 5 and Finn, 4. McDermott also has an 18-year-old son, Jack, from his previous marriage.
"Dean was saying, 'We just got Finn out of diapers; I thought we were in the clear!'" Spelling, 43, admitted with a laugh. "For the first time this year, they're all in school. So it's like, 'Wow. We're basically starting over.'"
McDermott, 49, acknowledged he and Spelling are going to have to buy a "Sprinter van" for their growing brood.
Despite recently celebrating their 10-year anniversary, the couple was forced to work through some serious issues about two years ago. McDermott had cheated on his wife back in December 2013 while away on a business trip to promote Chopped Canada.
Once McDermott came clean about his infidelity, a devastated Spelling contemplated leaving her husband while he hit rock bottom, sought rehab for depression and substance abuse, and even threatened suicide at one point.
Two seasons of the couple's reality series True Tori in 2014 basically served as raw on-camera therapy for Spelling. As difficult as the situation was, Spelling was determined to forgive her husband and hopefully forget.
Spelling insisted to People her marriage is now stronger than ever and she's thrilled about having another child.
"This baby happened at the best time," Spelling said. "Nothing is ever perfect, but I'm so madly in love with my husband and with our kids. The idea of adding to that is such a blessing."
Spelling is the daughter of Aaron Spelling, a famous Hollywood producer. In her career, she's starred in numerous reality TV spinoffs with McDermott as well as designed a jewelry line and released a memoir.
Spelling and McDermott wed in 2006 and began having children the following year.
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