If the couple already has a child/children and they do not want anymore the woman can have her tubes tied. If they don't take precautions as such and end up with a "mistake" they better be ready to deal with it, and NOT by 'getting rid' of it.
If someone 'accidentally' gets pregnant while on birth control AND using condoms (which I highly doubt this happens much, and if it does it's a VERY low percentage rate) then they still need to own up to their responsibility.
I think denuser answered this perfectly: