The speaker appears to be in need of an organ transplant (see dialysis, annotated in this database). Her son is the likely donor but there is an incredible irony in this: 30 years earlier she had tried to abort him, brutally ("the hangers I shoved inside"), before abortion was legal. Now, as she is told that her body might reject his, she remembers how she had previously rejected his body, and how he had refused to be rejected ("refusing my refusal").