I think the baby will get irreversible brain changes. Whether these changes are not suitable for life is another matter.
The indigenous psychedelic population of America, at least, traditionally feeds and drinks all sorts of ayahuasca and peyote since childhood. The dire consequences of this are unknown to me, and LSD in terms of the degree of danger, as far as I know, is slightly higher than traditional entheogens. And the dosages are tiny.
What will become of the baby's psyche is also a question. If a child grows up in such conditions that he is fed with acid from infancy and there will be nothing for the experimenter, it means that he is no longer in such conditions as other children, and from the point of view of the usual development of the child's psyche, he cannot be considered.
I think nothing terrible will happen, except for the still unexplored effect of chronic LSD use on a growing body.
Nobody knows, but let's try to guess.
First, among other effects, LSD inhibits sleep. Secondly, immediately after taking it, tolerance sets in to its new doses. These two factors do not allow us to constantly keep someone under the influence of LSD, so these will be periodic sessions.
Nobody gave LSD to children, or at least did not talk about it, but they did give it to animals. They cannot understand what is wrong with them, they panic, behave inappropriately. Then the action passes. Usually without a trace.
Two scenarios can be assumed. In the first case, the sessions will be a traumatic experience that leaves traces, this will negatively affect the development of the child. In the second case, they will pass without a trace and the child will adapt over time, because you can get used to the effects and learn to coexist with them.