I wouldn't consider drug use by a pregnant mom an ACE, at least while the fetus is still in the womb, though the drugs themselves could affect fetal development. I'm pretty sure it was Van Der Kolk, in "The Body Keeps the Score", that discussed the long term effects seen in children of women who were pregnant and at the World Trade Center in New York City, on 9/11, supporting the idea that trauma and increased stress hormones in a pregnant woman can affect fetal brain development, presumably just as ACEs do.
I'd say that a newborn taken away from its mother, in and of itself, isn't an ACE, but if whomever assumed care of the baby was not providing nurturing, then this neglect would be an ACE. I'm an adult medicine primary care doc, and have seen two cases of young adults who were born in Eastern European countries, put in foster care soon after they were born, adopted by seemingly nurturing, supportive American parents, but who both developed very disruptive behavioral issues starting in early in childhood. While these are far from evidence based, case controlled studies that prove a connection, it's hard for me not to presume that these kids were neglected during their time in the orphanages, leading to the ACEs-induced neurohormonal changes that we now understand causes long term health issues. I would think this neglect would also disrupt normal attachment, which could later be considered a maladaptive coping mechanism, presuming it affected the person's ability to connect with other people (though we're getting out of my field of expertise on the attachment issue).