Bill Rancic shows off Irish baby Duke on Twitter

Giuliana Rancic and husband Bill showed off their adorable son Edward Duke in a Twitter post which celebrated St. Patrick’s Day.

According to E! News, the proud father showed off baby Duke, who was born August 2012, with a mini-green mustache on Twitter.

“Happy St. Patrick's Day from Baby O'Duke #25percentirish @DukeRancic,” he wrote.

E! notes that Bill, 41, is of Irish and Croatian decent.

Giuliana and Bill, who have their own reality series, documented their struggles in getting pregnant following the E! News and Fashion Police cohost's battle with cancer. Following a double mastectomy, her doctor informed that they should wait five years before attempting to conceive. The Rancic’s then opted to try the gestational surrogate route - which was successful.

Three months after the birth of Duke, the couple revealed that they desire to expand their family even more in the future. At the time, she expressed during an interview with Today, “I had gone 37 years without a baby -- you know just focusing on myself and my husband and my career -- I didn't know how I would react when I had him in my arms. And it came so naturally."

Giuliana and Bill have not specified when they plan to try for another child.

Image: Bill Rancic Twitter