Let me be honest but like so often when this subject comes up i cannot help but feel it's a made up story. Anyhow i may be right or wrong. So...
If it was true i'd like to say the following... It's ridiculous to ask arbitrary folks on the WWW for consultation with a subject that personal and serious! You have to know what you're doing, and if you don't already find the answers by yourselves!
In my opinion you should closely listen to your own gut feelings. You can find a well-thought rational solution but from experience i know that ratio cannot outweigh emotions. So however you decide, your emotional makeup about the aftermath of your decision - whatever it may be - will probably remain and accompany you for many years of your future life.
Another important question is, how does your wife feel about it? Without having any details other than the few words you have mentioned here - which is definitely not sufficient in order to get the whole picture - i do not want to assume things. Just a few ideas of what your wife's undecidedness may mean...
i do not believe that she wants to abort because if that's what she wanted she would have done it already, and perhaps without even telling you, her husband. Also you say...
Does that mean she/you tried before but it never played out? In that case it is a gift not light-heartedly to give away.
But in the end it's her body - her choice, and you are not involved
until you actively claim your role in it. Her being undecided may possibly mean that she does not want to live the life of a single m0m. In that case she might be toying with two other scenarios. Scenario one: divorce you and raise the chi!d with the biological baby daddy. Scenario two: raise the chi!d as yours and hers within your marriage. Well the latter is not her decision alone because it depends on your decision as well. So can you imagine accepting the chi!d as yours and raising it as your own as part of your family? i believe her decision to keep it or not is dependent on if you commitedly and actively support that or not.
Anyway your wife is currently in a very vulnerable position and she depends on her husband's support either way (and - as far as i see it - it is also your
responsibility as the husband to be there for her).
Legally there is no issue at all because the husband will always be the fath3r of any baby his wife gives birth to unless he legally rejects it with proof it's not his. If you accept the chi!d there will also be no issue of whatever sort or form concerning your greater family. At least i can't see any.
Just my two's worth.