How do I protect my privacy from a lawyer who wants to disclose private info to my estranged husband?

I am a birthmother trying to get my sons adoption finalized, I need a lawyer who SPECIALIZES in adoption and can help me stop the lawyer of adoptive family telling my estranged husband information concerning the adoption.

The other answer is right if your estranged husband is the childs father all attemps to contact him must and will be used.
Its the law to contact the birth father. The attorney who represents the adoptive couple would not be doing his duty or his clients any favors not trying to make sure everything was done in accordance with the laws. A judge will not sign adoption papers until he knows the father is not wanting custody. You cant just give his rights away, only a judge can do that.
They will even run an ad in the paper where he lives for up to 6 weeks asking him to come forward if he intends to protest the adoption.
If after the ad has ran and he hasn't come forward the adoption can proceed without his permission.

If your estranged husband is the biological father, attempts must be made to find him and notify him of the proceedings or else the adoption will not be legal.

is he the father?

Who's privacy are you seeking to protect? Yours or your son's?

If the man is the biological father, he must be notified by law of the adoption, otherwise, he could eventually turn up and sue for custody, which obviously the adoptive parents would not want to have happen.