Having a baby is probably easier than giving birth to a phd thesis, although both takes months to 'prepare'. Yes some ppl take 10 months over even more to write a phd thesis.
During pregnancy, u get lots of moral and 'technical'(eg medical) support u need so u dont feel like u r going through all that by urself
Writing a thesis on the other hand, well at least from my experience, is a cold and lonely path :(