Beyonce & Jay-Z It's a Girl!! Blue Ivy Is On the Scene

1/7/2012 11:00 PM PST

Beyonce Gives Birth to Baby Girl Blue Ivy!

Beyonce finally popped, giving birth to a baby girl named Blue Ivy Carter in New York City on Saturday

Proud dad Jay-Z, real name Shawn Carter, was at the hospital where Beyonce reportedly birthed Ivy by c-section -- and shortly after her arrival ... J & B's famous friends started sending out birth announcements on the Internet.

Rihanna tweeted, "Welcome to the world princess Carter! Love Aunty Rih"

Hip-hop mogul Russell Simmons also took to Twitter, saying ... "congrats to my good friends Beyonce and Jay-Z."

Beyonce famously announced her pregnancy on stage at the MTV Video Music Awards back in August.

While initial reports had the baby name as Ivy Blue, now word is the name is actually Blue Ivy.