Have done the very briefest of reading from Barbara Creed’s chapter ‘Phallic panic: male hysteria and Dead Ringers.’
She writes of the origin of hysteria being associated with women, historically, given that it was medically linked (by Egyptians) with uterine problems, with abnormal movements of the uterus around the female body. Dead Ringers, then, reassociates hysteria with men by tracing it, in the two Jeremy Irons characters, to female uterine problems.
Then Creed writes, ‘The womb wandered around a woman’s body if deprived of moisture. […] The only way to keep the womb moist and prevent it from travelling was to keep woman’s body moist; and the only way to achieve this was to activate woman’s bodily fluids through constant sexual intercourse.’
Perhaps this is why the twins in the film wanted to sleep with their female patients (most notably, Claire, with the trifurcate cervix); in order to control her womb, thus prevent her uterine problems from manifesting as hysteria in themselves.
Freud wrote in Fetishism that ‘no male human being is spared the fright of castration at the sight of a female genital,’ so as gynaecologists, always in their presence, they strengthen their defences by remaining unified, by synchronising; even their hysteria.