The 'Countdown' singer gave birth to the couple's first child in January, but had yet to reveal any photos publicly.
© Tumblr / helloblueivycarter.tumblr.com
On Friday, Beyoncé and Jay-Z opened a Tumblr account at http://helloblueivycarter.tumblr.com, to which they posted five photos of the infant, including two with the stars themselves.
"We welcome you to share in our joy. Thank you for respecting our privacy during this beautiful time in our lives," read a hand-written message included on the site. The note was signed "The Carter Family".
The pair were recently rumoured to have filed a trademark application for Blue Ivy Carter's name after several third parties had tried to do so and failed.
Beyoncé made her first post-pregnancy appearance on February 6 while attending Jay-Z's two-night stint at New York's Carnegie Hall.
> Jay-Z gets emotional performing Blue Ivy rap 'Glory' live
