Vince Vaughn Welcomes First Child with Wife Kyla Weber

Are Hollywood's hottest actors getting a bad case of 'baby fever'? If Vince Vaughn is any indication, Hollywood has already set the stage for its own baby boom.

Vaughn, 40, and wife Kyla Weber welcomed Locklyn, their first child , into the world on Saturday, December 18. In January, the " Wedding Crashers " actor married Weber, a realtor, and announced her pregnancy later in 2010.

Vaughn, who had been romantically linked to Jennifer Aniston and Joey Lauren Adams, has a habit of choosing roles that portrayed him as a bit of a bad boy . In "Fred Claus," for instance, the actor played the somewhat naughty brother of Santa Claus.

These days, however, Vaughn has settled down and started a family. His upcoming film "The Dilemma" also casts Vaughn in a more mature role, that of devoted buddy who is afraid his best friend's wife is having an affair/

Vaughn's career and life choices indicate a growing trend among young Hollywood actors.

Matthew McConaughey, 41, now has two children, Vida Alves and Levi, with girlfriend Camila Alves. Prior to settling down, the " We Are Marshall " star averaged about two movies a year, but his filmography now shows gaps that coincide with his wife's pregnancy.

Like Vaughn, McConaughey's film choices also showed a tendency towards 'Peter Pan' roles and characters that refused to grow up. His character in the 2006 romantic comedy " Failure to Launch " even had a detailed plan for getting rid of girlfriends at the right time.

Yet, " Ghosts of Girlfriends Past ," a comedy loosely based on "A Christmas Carol," had McConaughey playing Connor Mead, a man forced to revisit his own questionable romantic past. After learning some painful truths about himself, he is finally able to find the right woman.

Parenthood hasn't changed workaholic Neil Patrick Harris much. With the help of a surrogate mother , Harris and long-time domestic partner David Burtka became parents of twins Gideon Scott and Harper Grace.

Harris, who completed hosting duties on Spike TV's 'Video Game Awards' last week, is still hard at work on "How I Met Your Mother," his successful CBS sitcom. Now a devoted dad in real life, Harris' character Barney Stinson is something of a womanizer on the show.

The domestic Neil Patrick Harris also is a far cry from the self-parodying role he played in "Harold and Kumar Go to White Castle." Harris portrayed himself as a Hollywood bad boy, a far cry from the doting father he has become.