The 36-year-old rocker, formerly of Cobra Starship, and Erin, 34, welcomed a son back in March (16), but they chose to avoid social media and the Internet in an effort to keep their pregnancy and baby news private, until now.

The fashion designer made the announcement on her website on Friday (06May16), and shared her journey to motherhood alongside a beautiful image of her while pregnant.

"I'm thrilled to report that I gave birth to a healthy, beautiful baby boy at the beginning of March this year," she wrote. "Many were unaware of this fact because my husband and I made a conscious decision to keep the pregnancy private for a few reasons.

"To us, pregnancy felt like a naturally concealed process. You know your baby is growing inside you, but you can't really see exactly what's happening. We took that as a cue from the universe to respect the mystery and secrecy innate in pregnancy," Erin explained.

"For that reason I chose to be very private during this time of my life. While this was mostly for the sake of the baby, it also suited me just fine as I found myself feeling incredibly vulnerable, shy, and self-conscious during my pregnancy."

The designer confessed that she felt "frumpy" while pregnant, but revealed that a chance meeting with Demi Moore, who famously posed naked while expecting, lifted her spirits and made her decide to shoot a series of candid pictures of her baby bump.

"I felt like a frumpy version of my former self, a far cry from the glowing pregnant goddess I had hoped to be," she continued. "The universe has an amazing way of speaking to us, and just two days before my due date I went to a friend's birthday party and ended up being seated next to Demi Moore!

"I had never met Demi before, but she had been on my mind that whole week as the ultimate pioneer and icon of the pregnant portrait. She spotted my ready-to-pop belly and with great conviction told me not to let the moment pass or I would regret it forever. So I decided this coincidence was too great to ignore and the next day I invited my friend Hellin over to shoot these candid portraits."

Erin, who along with husband Gabe has yet to reveal the name of their new son, gushed about how motherhood has changed her outlook on life as she prepares to celebrate her first Mother's Day in America on Sunday (08May16).

"It's truly the greatest gift," she added. "I wish that on this Mother's Day all women and mothers everywhere receive the love and appreciation they so deserve and more importantly, love and appreciate themselves."