It's Twins for Sam Trammell: Which Other Celebrities Are Currently Expecting Double the Trouble?

"True Blood" actor Sam Trammell and his girlfriend Missy Yager are expecting twins!

The happy couple has been dating for eight years and met doing theater in New York. Both have gone on to be successful on TV, with Sam Trammell playing Sam Merlotte on "True Blood" and Missy Yager appearing on shows like "Mad Men" and "Boston Public." With their recent good news, it seems that Hollywood is experiencing more than just a baby boom; it's seeing double the trouble with multiple celebrities being pregnant with twins. So who else will be seeing double in the delivery room soon?

Mariah Carey is currently carrying twins, and has revealed that she's pregnant with both a boy and a girl. She and hubby Nick Cannon haven't revealed the exact due date yet, the babies are expected to make their debut sometime this spring, and they're definitely going to arrive in style; Nick and Mariah have reportedly spent almost a million dollars on high-end baby wardrobes, cribs, strollers, and other necessities.

CNN news anchor couple Kyra Phillips and John Roberts are also expecting their twins to arrive sometime this Spring (probably just in time for Mariah's babies to rain on their parade). The couple has been engaged since last April. With two TV personalities as mom and dad, expect to see the newborns reporting the news of their own birth soon.

Actor Jeremy Davidson just revealed days ago that he and actress Mary Stuart Masterson are expecting twins. He currently plays Chase Moran on "Army Wives," while Mary Stuart Masterson's most recent role was on the TV series "Mercy." She is also known for starring in movies "Some Kind of Wonderful," "Fried Green Tomatoes," "Benny & Joon," and "At Close Range." Davidson said that the baby news was quite a shock, considering that the couple already has one child under the age of two. Masterson is currently four months along.

All of these bundles of joy will join a growing group of celebrity twin babies that includes Celine Dion's twin boys Eddy and Nelson; Jennifer Lopez' twins Emme and Max; Angelina Jolie's twins Knox and Vivienne; and Neil Patrick Harris' twins Harper and Gideon.

So it looks like the baby boom of 2011 just got bigger as even more twins become a part of this trend, and it's going to be fun to see if these pairs to come get great names like those listed above.