Marissa Mayer
Yahoo CEO Marissa Mayer announced this week that she and husband Zack Bogue are expecting twin girls in December. Above, Mayer is seen at the Metropolitan Museum of Art Costume Institute Gala 2015 in May in New York. Lucas Jackson/Reuters

Marissa Mayer is pregnant once again, and just like last time, the Yahoo CEO does not plan to take extensive time away from work. Mayer announced the pregnancy over Tumblr late Monday night, saying she and husband Zack Bogue are expecting to welcome twin daughters some time in December.

"The twins part was quite a surprise, because I have no family history of twins or any other predisposing factors," Mayer said on her Tumblr blog. "Zack and I have embraced the surprise and are very excited about these new additions to our family."

For Mayer, Yahoo and pregnancy have been tied together since she joined the company in 2012. She announced her pregnancy with son Macallister at the same time she was hired by the Sunnyvale, California, tech company. Mayer was lauded by some for proving women could have it all but criticized by others for setting a steep standard for women by taking just two weeks of maternity leave.

The Yahoo CEO calmed those critics nine months later by announcing an extended parental leave policy for Yahoo employees that gave fathers and mothers eight weeks of paid leave as well as an additional eight weeks for women and $500 to spend on items like baby clothes and groceries. In 2015, major tech companies like Netflix and Microsoft have been following suit by announcing extensive parental leave policies of their own.

As for Mayer, the Yahoo CEO said she has informed the company's board of directors and her executive team of her news and that they have all been happy for and supportive of her. "Moving forward, there will be a lot to do for both my family and for Yahoo; both will require hard work and thoughtful prioritization," Mayer said. "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."