Zachary Bogue and Marissa Mayer Credit: Andrew H. Walker/Getty Images

They’re here! Yahoo CEO Marissa Mayer welcomed her identical twin girls with her husband, Zack Bogue, in the early hours of Thursday, Dec. 10, and the excited second-time mom wasted no time sharing the happy news with the world.

“Zack and I are excited to announce that our identical twin girls were born early this morning,” she tweeted. “Our whole family is doing great!”

In a post to her Tumblr account, Mayer, 40, added, “Thanks to everyone for all of the support and well wishes throughout my pregnancy.”

Mayer and Bogue, also 40, first announced their baby news via Tumblr on Tuesday, Sept. 1.

“The twins part was quite a surprise, because I have no family history of twins or any other predisposing factors,” she explained on her blog at the time. “However, as I’ve now learned, identical twins occur by random chance in roughly 1 out of approximately every 300 pregnancies. Zack and I have embraced the surprise and are very excited about these new additions to our family.

The couple, who wed in 2009, reside in San Francisco with their 3-year-old son, Macallister.

In September, Mayer acknowledged that juggling motherhood and the company’s ongoing transformation would be no easy task, and noted that she would be “taking limited time away and working throughout.”

“Moving forward, there will be a lot to do for both my family and for Yahoo; both will require hard work and thoughtful prioritization,” she wrote. “However, I’m extremely energized by and dedicated to both my family and Yahoo and will do all that is necessary and more to help both thrive. The future looks extremely bright on both fronts.”

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics, and more delivered straight to your inbox!