Pique, who is regarded as one of the best defenders in world football, met Shakira in 2010 and performed in the music video for her song 'Waka Waka'.
Their relationship was not officially announced until March 2011 despite rumours, with Shakira falling pregnant in September 2012.
"The countdown begins! And we'd like to invite you to participate in our world baby shower joining efforts with UNICEF," Shakira posted on her official Facebook page.
Shakira, 35, is 10 years older than the Spanish international.