The following passage about Aylmer's dream foreshadows Georgiana's death:
He [Aylmer] had fancied himself with his servant Aminadab, attempting an operation for the removal of the birthmark; but the deeper went the knife, the deeper sank the hand, until at length its tiny grasp appeared to have caught hold of Georgiana’s heart; whence, however, her husband was inexorably resolved to cut or wrench it away.
This dream not only reflects Aylmer's compulsion to eradicate the birthmark; it further compels him to do so. He feels "inexorably resolved" to save his wife from the mark that mars her beauty. Although he does not use a knife to remove the birthmark, his efforts become increasingly extreme near the end of the story. And the dream's intensity closely parallels what is to become his reality. The more fervently he tries to get rid of the birthmark, the more stubbornly it stays. The tiny hand grasps Georgiana's heart, an image that symbolizes the close link between her imperfection and her mortality. To make a perfect being, Aylmer must kill the imperfect human. From this moment onward, Georgiana's birthmark haunts Aylmer at all hours of the day and night. It becomes his obsession, his central focus, and the point around which his scientific efforts converge.
Language matters here. The repetition of the word "deep" calls attention to the difficulty of removing a feature that is ingrained in Georgiana's being. The ambiguous pronoun "it" in the last sentence makes it unclear whether dream-Aylmer is compelled to wrench out her birthmark or her heart (in the end, her birthmark disappears as her heart stops). And the narrator ends every clause with a significant word—"birthmark," "knife," "hand," "heart"—creating a chiastic chain of emphasis that subtly reflects how the knife pursues the birthmark as the hand pursues the heart. The remarkable prose in this passage makes it a memorable moment to reflect upon when its foreshadowed event comes to fruition.