My brother is 18 and expecting a baby in the next few months and wants custody of the baby:) The girl is 19 and left him four months pregnant... and ever since she found out she was pregnant she wanted to get a abortion or give the baby for adoption and has been drinking and smoking cigaretts and weed even though she is pregnant... my brother has tried to stop her but she won't listen and he has no control over her... So he wants custody of the baby when he/she is born... this will be her third kid and two of them where taken away by child service and given to her family members... she does not try to see them or talk to them... and wants to her my niece/nephew up for adoption with out the baby been born... what can we do to get custody if she decides at the last moment not to give him/her up for adoption?

What state are you in because more and more states are putting baby drop off laws on the books. That's where with no questions asked someone is allowed to drop off a baby and that's all there is to it.

If he wants the baby , as soon as the child is born, he files for full custody with the courts and try and see what the courts will allow. If she does not want the child, she may be willing to let him have it

Also, since your brother is 18, if she decides to place the baby up for adoption, I strongly suggest he think of what's best for the baby and allow the adoption to happen. It's hard to be a teen-age unwed mother. I think that it has to be a lot harder to be a teen-age unwed father with sole custody. Especially since the mother will be able to sue for visitation, etc. at some point in the future.