Ekoria was a Teplan who was infected with an affliction called the Blight, a disease created by the Jem'Hadar to punish the Teplans for resisting the Dominion. Once the Blight quickened, the Teplans sought out Trevean, who poisoned those who were quickening in order to end their suffering.
In 2373, Doctor Julian Bashir and Jadzia Dax transported to the planet's surface, where they encountered Ekoria. Ekoria sought Bashir's help; she was pregnant, and wanted to live to have her baby. She volunteered to help him find a cure for the Blight. He injected her and others with a serum he hoped would be a cure. But Ekoria got worse and the others died. Ekoria then knew she would die before the child could be born, and she allowed Bashir to induce labor. Trevean visited her and asked if she wanted him to help her die, but Ekoria refused.
Sadly, Ekoria died in childbirth, but not before she saw her baby, who had no sign of the Blight. Bashir's antigen had not worked on her, but did on her baby. She knew that her child would lead a normal life. The fetuses of pregnant women could be vaccinated against the Blight, leading to a generation of healthy Teplans. (DS9: "The Quickening")