RELATED: Double Trouble: Celebs With Twins
The pair became mom and dad to two "healthy, baby boys" on Tuesday, People has confirmed.
According to Life&Style, "The couple is very happy that everything went smoothly."
RELATED: Selma Blair Welcomes a Baby Boy
Trammell recently expressed his trepidation about the prospect of welcoming two little ones at once. "I'm about to have twins," he told New York Magazine's Vulture column. "I'm absolutely terrified, and they're boys, too. The fear level is pretty high."
Yager -- who has previously appeared on "Mad Men" -- and Trammell have reportedly been dating for eight years.
Related stories on ETonline.com:Bill O'Reilly Guest Stars on 'Rizzoli & Isles'
- Feb. 03, 2016 See all the reasons we love Grammys host LL Cool J!