News that the songstress had given birth, which was first reported by People magazine and US Weekly, ignited social media, with the so-called "Bey hive" fan group buzzing over the yet unrevealed sexes and names of the latest additions to the Carter Clan.
Entertainment news outlet E! said the power couple was spotted at a Los Angeles area hospital on Thursday.
Speculation grew when an unidentified woman was photographed Friday carrying a large bouquet of pink, blue and purple flowers -- complete with a card that appeared to read "B + J" -- along with twin pink and blue balloons in the shape of feet that read "Baby Girl" and "Baby Boy."
Superstar Beyonce in February made the blockbuster reveal that she was expecting.
Clad in panties and a bra under a flowing veil, she commanded control of the internet by posting a picture of herself kneeling beside a human-size floral arrangement, her hands cradling her rounded belly.
"We would like to share our love and happiness. We have been blessed two times over," the 35-year-old singer wrote.
"We are incredibly grateful that our family will be growing by two, and we thank you for all your well wishes," she added, signing with Jay Z.
As an expecting mother she made a New Age celebration of women at the Grammy Awards earlier this year -- putting on an extravagant and abstract performance while proudly displaying her baby bump cloaked in a flowing gold gown.
She made a number of red carpet appearances while carrying the twins, and documented her pregnancy via social media to the joy of her legions of adoring fans.
