Jay Z, husband of Beyonce , has confirmed that his wife is pregnant with twins .

The 35-year-old Halo singer - who already has daughter Blue Ivy with the rapper - made the shock announcement on Wednesday posting a stunning portrait of her baby bump on Instagram as she shared the touching news with fans.

"We are incredibly grateful that our family will be growing by two, and we thank you for your well wishes. The couple - who have remained defiantly strong despite rumours surrounding their marriage - tied the knot in 2008.