Beyoncé and Jay-Z have welcomed their first child – a baby girl. Reports out of New York say the singer went into labor last night at Lenox Hill Hospital on the Upper East Side.

TMZ is reporting her name as Ivy Blue Carter …although some reports say Blue Ivy Carter. The baby was reportedly delivered via a scheduled C-section. Baby and Mom are doing well according to sources at the hospital.

The Daily News received reports from staffer at the uptown hospital that a pregnant Beyonce checked in to the hospital under the alias of Ingrid Jackson.

Beyonce and her hip-hop hubby, Jay-Z, rented out the hospital’s entire fourth floor for $1.3 million, the employee said.

In an effort to keep images from leaking to the public, hospital workers placed tape over security cameras and are forcing employees to turn in cell phones when they arrive for their shifts, the source said.

Several security guards were spotted patrolling the outside of the hospital Saturday night.

A Lenox Hill staffer confirmed that a patient named Ingrid Jackson was in a “labor room.”

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.”

Diddy tweeted: Congrats to jay and B! God Bless 🙂 ! And many more!

Congrats Jay & Bey!!