Baby girl born to Beyonce

Singer Beyonce Knowles has given birth to a baby daughter.

According to contactmusic.com, the 30-year-old delivered the girl, named Ivy Blue Carter, in Lenox Hill hospital here Saturday night via a scheduled Caesarean section.

She's the first child of Beyonce and rapper husband Jay Z, who got married in April 2008.

Rihanna was among the first to congratulate through micro-blogging site Twitter: 'Welcome to the world princess Carter! Love Aunty Rih.'

Hip-hop mogul Russell Simmons also tweeted, 'Congrats to my good friends Beyonce and Jay Z.'