Christina Aguilera has named her daughter Summer Rain.

The singer -- who already has a six-year-old son, Max, with her ex-husband -- welcomed the little girl into the world on Saturday. She is now "proud" to announce the baby's name.

She tweeted Sunday: "So proud to welcome our beautiful daughter Summer Rain Rutler into the world."

It is believed the 33-year-old star had her daughter via Caesarean section despite being keen to have a natural birth.

A source said last week: "She's due at any moment. But she's freaking out because with her first child, Max, she had a C-section. This time, though, she wants to have a natural childbirth."

The 'Voice' mentor announced in February she was expecting a baby with fiance Matt Rutler.

The happy news came one week after Rutler proposed to the beauty in the backyard of their Los Angeles home on Valentine's Day.

Meanwhile, Aguilera recently showed off her pregnancy body in V magazine and admitted she is very "proud" of her figure.

She said previously: "As a woman, I'm proud to embrace my body through all stages of life, staying fearless and confident in surrendering to the unknowns the future has in store."