Based on the above interpretation of their relationship being oedipal, it could be argued that the reason Macbeth was so disturbed by the image of his wife smashing in their child’s head had nothing to do with any fictional
child, but everything to do with the idea that Macbeth was the child. She'd "given suck" to him, and knew how "tender 'tis to love the babe"
that milked her, but she'd kill
him if he didn't do what she said.