Martina Levato, 23, and her partner Alexander Boattcher, 30, are serving 14-year prison terms over a December 2014 attack that left their victim third degree burns and in danger of losing an eye.
At the time, Levato was already pregnant with the son she gave birth to at the weekend.
She was not allowed to even hold the newborn before he was taken away on the orders of a Milan prosecutor.
"I'm desperate, they have destroyed me", Levato was quoted as saying by her lawyer.
The prosecutor who ordered the removal of the baby boy has also initiated adoption proceedings, although these will have to be approved by a family court.
He was quoted as describing his decision as "a humane act taken out of solidarity with the baby." It followed advice from psychiatrists who had interviewed the mother.
Levato's lawyer said it was not consistent with established precedent under which a child would only be removed from a prisoner mother so early in its life if she was drug or alcohol-dependent.
Before the surprise move it had been envisaged that Levato would be moved with her son to a special mother-and-baby prison unit.
Much of the extensive media comment on the subject was critical of the decision not to leave the baby with his mother, at least temporarily.
"Do reasons exist to take a mother's right to hold in her arms the creature she has just brought into the world," asked La Repubblica.
"Do reasons exist to deprive a child of his right to feel welcomed by she who gave him life. Does a stronger law exist than the law of nature?"
Levato has a number of other cases involving threatened or actual acts of violence pending.
During her trial, prosecutors claimed the former student at Milan's private Bocconi university had planned to castrate another ex-boyfriend.