Why do you write "adoption" in English
and then go on in Spanish? This is an English language board. You don't get points for knowing the language.
There are just two possibilities:
1) You get a friendly doctor to give you a certificate of birth that you had the baby,at such-and-such Clinic, have your husband take that to Registro Civil and declare the baby as yours, then take the DR Birth CErtificate over to the US Consulate and declare the birth there, get a US Passport + Social Security Number, and take it home. (Since there are several Federal Crimes in this method, I cannot say that you should do this, nor is this to be construed as legal advice.
2) You can go through the process and spend thousands of dollars and three or four years trying to do it a legal way. You are not first on the list and there are people that have been waiting for years for a baby.
NEXT QUESTION??
HB
Just one precaution: It is quite possible that the US Consulate will require a DNA test to make sure the baby is yours..