SHAFAQNA – The Grand Ayatollah Sistani answered a question about adopted child becoming Mahram to adopting parents.
Question: If husband and wife adopt a child and the wife takes tablets to produce milk in order to breastfeed the child, does the child become Mahram to the woman and her husband?
The Grand Ayatollah Sistani: (The child) does not become Mahram.
Source: PERSIAN SHAFAQNA