The message was accompanied by several hashtags including #birthday #beyonce #jayz #twins and #happybirthday. As we've previously reported, sources close to the couple confirmed to People late Saturday evening that the twins had been born.
The music power couple are already parents to five-year-old daughter Blue Ivy.
The caption next to the post read, "We would like to share our love and happiness".
Paul Casey part of 4-way tie atop US Open
Yet Johnson was forced to bide his time for the next six holes, unable to convert the few birdie chances that came his way. Only a half-dozen of them have even experienced Sunday contention in golf's biggest events. "The golf course is great".
Bey and Jay-Z are believed to have welcomed their two tots earlier this week, but in true Knowles-Carter style, have continued to be tight-lipped on their new arrivals. TMZ adds that the family has yet to return home, though the issue keeping the babies at the hospital is said to be a "minor" one.
The celeb baby news quickly soared as a trending topic on Twitter and broke the Guinness World Record for Most Liked Image in the social media site's history.
The pair have remained relatively silent throughout the pregnancy but Beyonce's mother Tina Knowles hasn't been able to contain her excitement.
Reports she had become a mum began swirling this week when rapper Jay Z missed his Songwriters Hall of Fame induction on Thursday night. The "Formation" singer's father said he was "shocked" but "happy" to find out she was expecting. She didn't go dark altogether, however, and even hosted a "Carter Push Party" in May to celebrate their impending birth.
On doctor's orders, Beyoncé was forced to pull out of her Coachella headlining set and reschedule for 2018.