Selma Blair Welcomes a Son
07/26/2011 AT 05:05 PM EDT
The actress, 39, and her fashion designer boyfriend, Jason Bleick, welcomed son Arthur Saint Bleick on Monday, her rep tells PEOPLE exclusively.
Arthur weighed in at 7 lbs., 12 oz.
The couple, who met when collaborating on Bleick's line EVER, announced her pregnancy in January. Blair chose to keep the sex of her baby under wraps until the delivery.
"I'm not going to say what it is yet. Hopefully, it's one or the other," she joked with PEOPLE.
The actress was recently nominated for a Grammy for Best Spoken Word Album for Children for the audio book Anne Frank: The Diary Of A Young Girl: The Definitive Edition.
Reporting by JULIE JORDAN