Cabawill just summed it up correctly.
If they go through the formal adoption process, a lot will be made clear to them.
Look up Foetal Alcohol Syndrome, it's shortened just to FAS sometimes. It means the child's mother was an alcoholic and kept drinking throughout the pregnancy.
Some drug addicted mothers smoke a couple of crack pipes before giving birth to help with labour pains.
Some babies go into withdrawal after being born because they are no longer getting the illicit drugs from their mother via the umbilical cord.
Mothers that have been subjected to stress i.e. domestic violence etc all through their pregnancy have already shown that they are not able to keep the baby safe. That's before it's even born.
Babies that have heard arguments, shouting, violence etc are traumatised and will carry that with them for a very long time.
There are fifty thousand children in the care system in Britain. That's a minimum of fifty thousand parents who cannot or will not parent their children properly. Well, unless they are dead or in prison or in residential health care.
There are regular stories of a child/ren that get murdered by their adoptive parent/s. No offence to the OP's friend.