I think there are rather few works where the dead baby is actually a main character (though I think arguably the dead baby in Steinbeck's The Grapes of Wrath is symbolic of a major theme in the work. Likewise Upton Sinclair's The Jungle). The references can be rather limited (though they do tend to be quite shocking). In Iain Banks's The Wasp Factory, for example, we meet one dead baby only briefly while the narrator, a homicidal castrato teenager, is explaining how his older brother was driven insane. This baby, a patient in a hospital suffering from hydrocephalus with only a steel plate protecting his brain, smiles dreamily as the brother realizes that a nest of maggots has made its way under the plate, and then, in a fit of shock and despair, attempts to remove the larvae from within the child's brain with a spoon. That's the kind of reference we're looking for.