Anne Wojcicki is 45 minutes late, something so encoded in her habits as 23andMe’s CEO that employees have stopped complaining about it. They know it’s hardwired. On a Thursday morning in April, her team is waiting patiently as she swirls into the company’s headquarters wearing running shorts, a T-shirt that says “Yay DNA” and worn tennis shoes, having just pedaled the 5 miles to work while eight months pregnant.  Reflecting Wojcicki’s passions, 23andMe’s headquarters, in Mountain View, California, looks like a cross between a Silicon Valley startup and a fitness club. There are treadmill desks throughout the open-plan office, elliptical machines in conference rooms and Peloton bikes in the cafeteria, which connects directly to a gym. Wojcicki is still practically bouncing after climbing the four flights to her small glass-walled office, pausing only to fill up her metal water bottle. She makes sure her employees know that their well-being is their own daily choice. “I’m like, ‘I take the stairs and I’m pregnant! You can take the stairs!’ ” Wojcicki says. Such a workout would be a lot for most expecting moms, but Wojcicki, who’s 45 and has two children with her ex-husband, Google...