How flexible job B is? Short commute is definitely a plus with kids, but more important is flexibility.
I had short commute when my twins were born, I used to go home to feed my kids during lunch instead of pumping. Very convenient. But it was dead end job, so once kids got older - I quit for more promising position with longer commute.
In your situation - I would pick A - child is just planned (you don't know how long it would take), 3 days telecommute is awesome, and great coworkers are a must for your mental health (it is quite important during postpartum, ask me how I know

)