Yahoo CEO Marissa Mayer delivers a baby boy by Patricia Sellers @FortuneMagazine October 1, 2012, 3:04 PM EST E-mail Tweet Facebook Google Plus Linkedin Share icons Marissa Mayer delivered a baby boy last night. The Yahoo CEO’s husband, Zachary Bogue, Tweeted this morning: “Baby boy Bogue born last night. Mom ( @ marissamayer ) and baby are doing great–we couldn’t be more excited!” Mayer’s executive assistant, Trish Crawley, tells me that they welcomed baby Bogue at exactly 22:22, or 10:22 p.m. For Mayer, a math geek with a Masters in computer science, 22:22 means something, though we mortals have no idea what. Mayer is on the cover of Fortune‘s Most Powerful Women issue, on newsstands now. She ranks No. 14 on the MPW list. That’s way up from No. 38 last year, when Mayer was a VP at Google (GOOG) with hardly a clue that her life was about to change. Mayer, 37, broke the news of her pregnancy to Fortune last July, a few hours after Yahoo named her its new CEO. What’s ahead for Mayer? Multitasking! She told me in July: “My maternity leave will be a few weeks long and I’ll work throughout it.” Indeed, restless investors are waiting for that Yahoo turnaround.