Both stories are at their cores about women in unhappy, unequal marriages. While Mrs. Mallard and Desiree both love their husbands, they are not allowed to be their equals. Mr. Mallard dominates Mrs. Mallard; even though he is not a bad or abusive man, he is still in control of everything Mrs. Mallard does and she realizes that being widowed will allow her to take hold of her own destiny. Should she want to travel, she does not need the permission of her husband. Desiree is even more dominated by Armand, to the point where she does not stick up for herself or her own child when Armand banishes them from his life due to the child's clear mixed ancestry.
Both women face death as a result of male tyranny. Mrs. Mallard has a heart attack when her husband comes home alive, both from the sudden shock of his appearance and from her dreams of liberation being dashed. "Desiree's Baby" ends more ambiguously, with Desiree's adopted mother bidding her come home and Desiree leaving Armand's estate...