What role does Antigone's womanhood play in Creon's sentence in Antigone?
In Antigone, gender plays a critical role in who can openly question Creon as ruler and who can die.
Remember, at first Creon sentences both Ismene and Antigone to death sentences. Creon says:
Creon seeks to punish both sisters for establishing a female community against him more than any criminal act against the state. In other words, it doesn't matter to Creon who buried and who did not; he seeks to punish the entire gender. "They must be women, and not range at large" means that women are not women unless imprisoned--such is the vaunted male pride and sexist double-standards toward women.
Later, it is the Chorus who reminds Creon that Ismene is innocent of the crime of burying her brother. Otherwise, she would have died as well.
According to Enotes:
As Arlene W. Saxonhouse noted in her Fear of Diversity: The Birth of Political Science in Ancient Greek Thought: "Creon, the political leader, categorizes and simplifies; one female equals another.... In a perverse way, Creon's refusal to distinguish, to particularize, to see differences, may make him more the democrat than the tyrant." This difference of opinion serves to underscore how complex the play is. Whether one perceives Creon as tyrant or democrat, he meets a tragic end.
So, Creon allows Haemon and the Chorus to challenge him, but he does not allow women to disobey him without punishment.
The previous post was quite accurate. I would only add that part of what infuriated Creon was that he was unable to convince a woman that she was wrong. Antigone ends up proving to be Creon's equal in magnitude and conviction of belief. This is something that was not meant to happen in Greek society, where gender lines were clearly established. Such is the case with Ismene, who takes the traditionally bound approach in trying to tell Antigone to not pursue her claims against Creon. In the end, Creon is angered that someone would question his authority and it had to have added to this antagonism that it was a woman who was acting as the agent of action.