All “abnormalities”? What would qualify as an abnormality? Not that I would in any case approve of mandatory requirements for all pregnant women.
Seems to me that almost all women who are pregnant or considering it, become about as interested in information and doing the best for their child, as just about any human is ever concerned about anything.
That is, if as you say, ”doctors discovered that the right amount of a certain vitamin or chemical is the cause for children being born either with a physical or mental difference from what is considered normal”, and if “what is considered normal” is something like not having deformities or health problems (and not some wacko subjective nonsense), then I think all you need to do is let the pregnant women know that.
If there are some pregnant women who respond to that information by choosing to do the opposite, then I expect either they have another theory or opinion that deserves consideration, or they are apathetic or resentful about the pregnancy, and probably want psychiatric counseling or possibly an abortion or adoption or something, not to be overpowered by laws.
Making laws to require pregnant women to do the “best” things for their unborn children, seems like a strange thing to do. It also seems like inserting a government in the middle of the relationship between mother and unborn child, which seems like a horrible thing to do – this is also one of the many reasons why I think abortion rights should absolutely be up to the mother.
Another reason I think this sort of proposed law is a horrible idea, is because it’s trying to control and assert authority where it is naturally practically impossible to do so, ultimately, and where doing so will, I think, cause cases of resentment with the potential for far worse impact than what the law might hope to accomplish. That is, if I were a pregnant woman, and I for whatever reason disapproved of the “normalization drug”, or wanted an abortion, and the government told me I couldn’t do as I felt was right, I would resent the heck out of that imposition, and as the mother, there is no way my resentment would not show up in the child’s life in one way or another. For example, for some women, this could include drinking lots of alcohol or other behavior that could cause birth defects, miscarriages, and of course abuse and unhealthy relationships during childhood. So don’t mess with mothers like that – the children will pay for the unwise laws.
All of the above relates to a reasonable, benevolent definition of “normal”. But if the definition is instead ”mental difference, like being a savant, or passionate, or artistic, or violent. Just a normal, absolutely boring person.” then I think the people proposing such a law are Orwellian nightmare zombies, who I’d far rather were eradicated than passionate savants with six toes!