What you tell – how much of the intimate details (of why you decided to adopt and whatever you know of your child’s history) you want to share with others is upto you. But, what you share and the manner in which you do it will definitely reflect your own mindset.
If you are ashamed and secretive about it, people will try to find out or make up their own juicy details to use to gossip. If you are open and transparent about it, people won’t have much to gossip about because you have already told everyone the truth directly. In order to send out a united and confident message to the world, you and your spouse need to be on the same page and at peace with why you have decided to adopt and how you intend to raise your child to be confident with this truth. This holds true in the case of single parents too. Tell the truth. Anything other than the truth may only cause more confusion and pain.