Watch the video to find out all the details!
The 39-year-old actress is already a mom to 5-year-old Cyrus Michael Christopher, who she shares with her husband, English actor Hugh Dancy.
Now, the couple is expecting baby no. 2! The former My So-Called Life star told Howard that she's "seriously preggo."
"I’m deep into my second trimester," she said, confirming that this was her official announcement.
When Howard asked if the second child was a surprise or planned, Claire said, "Yeah, this was planned. We’ve been wanting another kid for a while, and it happened."
Claire is going to keep the gender of the baby a secret for now. She joked that she'd name the baby after Howard, “Howardina” if it’s a girl.
What do you think about Claire's baby news? Let us know in the comments!