It's a boy for former E.R. star Julianna Margulies and her lawyer husband Keith Lieberthal. Heartiest congratulations to you both!

Once again, it's the proud grandparents who are trumpeting the news to the world. Keith's father, Dr.  Kenneth  Lieberthal says: "Obviously I’m utterly delighted to be a grandfather. I have to say, he is cuter than any other baby I’ve seen.”

Margulies’s mother was more restrained. "I better not open my mouth. I don’t want to get in trouble with my daughter,”  she told PEOPLE magazine. But she gives it all away in her voicemail message, announcing: “A beautiful baby boy has been born to us. All is well. His name is Kieran Lindsay Lieberthal. Is that poetry? Do a little dance. Love this day! All is well. God bless! Can’t wait to hear from you.”

Margulies, 41, and Lieberthal, 35, were married in November 2007.  This is the couple’s first child.

[PEOPLE]