“Body Parts” is episode twenty-five of season four of Star Trek: Deep Space Nine.
Quark has returned from the Ferengi homeworld with news that he’s got a rare illness, and there’s no cure. So he’s dying. Rom suggests that he put his remains up for sale, as is the Ferengi custom, and Quark agrees. When someone bids 500 bars of latinum for his dessicated remains, Quark quickly accepts his offer.
Then, the doctor who game Quark the diagnosis tells him he’s made a mistake, and Quark doesn’t actually have the illness. However, it turns out the Liquidator Brunt of the FCA was the one who bid on Quark’s remains, and he comes to the station to collect them. The fact that Quark isn’t actually going to die is irrelevant; either Quark fulfils the contract (gives Brunt his remains) or Brunt will take all his assets.
Meanwhile, Major Keira, Dr. Bashir and the pregnant Keiko O’Brien are returning in a runabout from the Gamma Quadrant. The runabout is damaged, and Keiko was injured. In order to save the baby’s life, Julian transplanted it into Major Kira – and she’s now going to carry it to term. This was actually done because Nana Visitor, the actress who plays Major Kira, was herself pregnant, and this gave her a reason to continue working without having to hide her pregnancy.