"Leave" forever or go on maternity leave?
Most districts will allow you at least one semester of unpaid maternity leave, you paying for the benefits while you are on leave.
If you intend to Leave for good, you'll probably get a poor reference; and it will be on your employment record that you only worked for district from Sept 1, 2001 - December 1, 2001.
If you are not serious about establishing a career, I advise you not to take the teaching job if you intend to quit forever.
Sorry.