Thesis baby (noun): Any child born within a year of one's thesis defense - generally after.
I defended my thesis when 35 weeks pregnant with my own thesis baby. Successfully, even. (I did bike to work that summer and removed the baby-related chub.)
(I have completely forgotten what my point was. Maybe: Thesis Baby! Everyone should have one! If you want and you can and so on. Plus, it's an excellent excuse for My Defense Must Happen By This Date So Help Me God. Also effective: lease expiring, spouse leaving town, parent who is ill, or a general extremely-cheesed-off-at-grad school feeling.)