The happy couple, who married in a top-secret wedding ceremony in New York City in April 2008, are also the parents of 5-year-old daughter Blue Ivy. Beyoncé famously announced her first pregnancy at the 2011 MTV Video Music Awards.
"Being pregnant was very much like falling in love," Queen Bey said in her 2013 HBO documentary Life Is But a Dream. "You are so open. You are so overjoyed. There's no words that can express having a baby growing inside of you, so of course you want to scream it out and tell everyone."
Beyoncé's mom, Tina Knowles Lawson, also took to Instagram on Wednesday to congratulate the expectant parents. "WOW I don't have to keep the secret anymore," she wrote. "I am soooo happy God is so good twin blessings."
Last year, the pop superstar made headlines when she released her acclaimed visual album Lemonade, which showcased the betrayal of a romantic partner, prompting fans to speculate that Jay Z, 47, had been unfaithful with the so-called "Becky with the good hair." At the end of the hourlong film, the couple seemingly made amends as Beyoncé sang, "True love breathes salvation back into me / With every tear came redemption / And my torturer became my remedy."