I have 3 kids through domestic infant adoption/ I also used an attoerny ( but they work just like an agency).
I understand your concern about contact but in many cases, the birthmom is the one who stops the conact after birth. You will limit your opportunities for adoption if you reqest no contact after birth. My attorneys advised us to be very non committal about the amount and frequncy of contact and let things work out as they may.
You may find that after you want some minimal contact after the baby is born. Take a look at the artical a few posts down it may give you some additional persepective.
I have 2 sons and a daughter, I have frequent contact with the birthmom of the 2 boys ( same birthmom). She has become a personal friend but since we do not live close the contact for the most part is over the phone. My oldest is 3 1/2 and the baby is 10 months. When the baby was born, I brought my oldest boy to meet his birthmom. he knows her as Miss melissa and as a family friend.( no a birthmom at this point)
I did not get a chance to meet my daughters birthmom at the birth or even after. she contacted the law office and requested pictures almost a year later and shortly before the birth of my youngest son. I sent her a letter and offered to meet her since I would be in the area for the birth of the baby. I had really regretted not getting a picutre of her or a cnahce to meet her at the birth. We got together and had a wonderful chat. One month later I returned with my daugher ( I from Massachussetts and adopted in Oklahoma). I gave her our address and phone number but have not heard from her since. I think the sepration was even harder the second time and she is trying to move on.
My thoughts are that I do not want the birthmoms to be a mystery to my kids
and some contact with the birthmom ( controlled and from a distance) will help make it that way,