The rapper, who grew up as Sean Carter, took to Twitter to thank artists who had influenced him as well as former United States president Barack Obama.
TMZ reported yesterday that the newborns have spent the week in hospital with a "minor issue" because doctors don't "feel comfortable" releasing them. Beyonce better put her family in their place before it costs her personal happiness [sic]'.
According to the NHS, jaundice is common and usually harmless in newborn babies.
Over the weekend, confirmation went viral about Bey and her hubby Jay Z welcoming twins together.
As if to confirm that the twins are doing OK, father Jay Z wasn't looking too anxious when he was spotted heading into and out of a Soul Cycle class in West Hollywood Monday morning, the Daily Mail reported.
According to TMZ, the babies were born "prematurely" and are being "treated for jaundice".
"They're here! #beyonce #twins #jayz #happybirthday, love grandad", the proud granddad captioned with a photo of balloons and a birthday wish posted to his account.
The announcement got more than 8 million "likes" in the first 24 hours to become the "most-liked" Instagram post ever.
Beyonce has kept a low profile in recent months, dropping out of Coachella (she was replaced by Lady Gaga) in April and skipping the New York Met Gala in May.
"Blue is happy and can't wait to take the new babies home to play with", the insider added.