I was very lucky to take a 10 month maternity leave and it felt almost right. I support stay at home moms and working moms and I don't want anyone to have to chose between the two if they don't have to. Why not consider staying at your job (if possible), but taking a leave of absence?
Here's my 12 reasons why maternity leave should be 12 months:
12) You need 12 months to get your own body back to some state of normal. Not sleeping and working long hours are not conducive to a healthy body (or mind).