Before birth the human being is still in the protection of Beings who stand above the physical. It is to them that we must leave the immediate and individual relationship between the world and the human being. Hence a pre-natal education cannot be addressed to the child itself. It can only be an unconscious result of what the parents — especially the mother — achieve.
If until birth the mother behaves in such a way that she brings to expression in herself what is morally and intellectually right, in the true sense of the word, then of its own accord what the mother achieves in this continuous self-education will pass over to the child.
The less we think of beginning to educate the child before it sees the light of the world and the more we think of leading a right and proper life ourselves, the better will it be for the child. Education can only begin when the child becomes a true member of the physical world — and that is when he begins to breathe the external air.
Source: Rudolf Steiner – GA 293 – The Study of Man – Lecture I – Stuttgart, 21st August 1919