Reentry?

Hello, I have a green card that is valid for another five years. I now plan to go back to my birth country for a while to have a baby. I do not know for how long but if everything goes well for less than a year.

My question is - what if I for some reason have to stay away longer? Should I apply for a reentry permit before I leave just in case? However, if I do not stay away longer than a year that seems unnecessary?

Is is possibly for me to leave the US and once I know weather I have to stay away longer than a year apply for an extension at the US embassy in my home country?

I would be very grateful for any advice. I have no intention of misleading anyone. I simply do not know yet how long I will need to be gone. I do not want to start a long, and costly, process of applying for a reentry permit before I leave if it is not completely necessary. Also, I really can not afford to loose my green card so I want to do this by the book.
Thank you in advance!

[olive]

See Green card: Abandonment of residence: WORLDLawDirect - Green card: Abandonment of residence