One can always think that an implication can equate a possibility. The role of the unborn baby in The Comedian is inevitably the symbol which envelops Corinne's life.
Based upon the fact that L'Heureux typically centers his stories around ordinary events which, in the end, become something surrounded by extraordinary circumstances.
The story follows Corinne's life after she finds out that she is pregnant. Pressured by her husband to abort the baby, Corinne, instead, embraces the unborn child. The child beings to sing to her from the womb. It is only when Corinne admits that the singing is her imagination that the child becomes silent.
When charged with the possibility that the child may be deformed, Corinne must decide to keep or abort the child. At one point, Corinne decides to abort her baby. Falling into a downward spiral, Corinne realizes that she cannot go through with the abortion. She shouts aloud that she wants to keep her child. This moment changes Corinne's life forever.
The importance of the unborn child is somewhat hidden in regards to the question: Is a baby born dumb? The implication regarding the child actually points in a very different direction.
One could justify that the baby is, indeed, very smart. The unborn child leads Corinne through life with its song. It is only when she denies the singing that the child becomes quiet.
After renouncing her previous statement, and deciding to keep the child, the baby takes control of her life again. Without the child, Corinne cannot be happy.
Therefore, disregarding scientific thought, one could say that the text actually proves that a child is not born dumb. Corinne's child proves that it has wisdom far beyond its age.
I read that the child is born unable to vocalize thought. That does not mean that the child was unintelligent. It adds to the irony that the author handles so skillfully.