a woman, very pregnant, a week or two overdue, gets kidnapped. Maybe she's beaten in a dark alley, then tied up and dragged to a truck of a car. She's injected a medication that'll kickstart her labour. Her hands are tied behind her back and her thighs are tied shut. She's gagged and a bag is put over her head. Truck is shut and the drive begins as her labour starts.
They drive for hours. 8 in total, not that she can tell. She's too busy being uncomfortable and in pain. She's scared, and the truck feels too small for her too pregnant body. The drive makes her body jostle painfully in the truck. She's too big to change positions while tied up. Worst yet, the fact that her labour has began: she feels her cervix open to expel the heavy load in her womb, slowly, over the course of the drive. Her water pops, and it soaks through has underwear and pants. Eventually, the contractions start. She can't not push, and despite being unable to spread her legs, she pushes. Over and over again, screaming into her gag. Her stomach visibly moves with her contractions and she uselessly pushes, unable to make room for the child to exit her. The head can only barely get through the cervix, stuck in her painfully stretched vaginal canal, as there's no space to advance.
When the drive comes to an end, she's already been pushing for hours. The truck is opened, and more than one person is talking. She's lifted up and the ropes on her legs are cut. She tries to open her legs and squat, finally able to make enough room to give birth, but is stopped and forced to walk. She waddles, legs spread as wide as possible, and stumbles forward with her captors, attempting to stop to push with her contractions but not allowed such luxury.
They get inside a warehouse. She still has a gag and a bag over her head, so she can't see where they are. All she knows is being pushed to cold, concrete floor and feeling her clothes cut from the front. She feels her tits spill out from their confines, swollen, big and heavy with milk. She wails into her gag, pushing again. Her hands are still tied and she's still wearing pants. Her captors let her push, until she's screaming with a painful crown. She keeps pushing, but the head in her cunt is stuck. It pushes against her pants, too tight to let the baby come out. She writhes and squirms on the floor with no avail.
Her captors take the bag and gag off, berating her. Saying she's one pretty looking slut, how fuckable she looks while giving birth. She'll be a fine breeding bitch for them. She begs for them to get her pants off. They laugh at her. If she sucks their dicks well enough, they might let her give birth. Disgusted and unwilling but desperate, she starts sucking the cocks shoved in to her mouth, one after another. She sucks with desperation that her captors call enthusiasm, and cries as they humiliate them and fuck her throat. She can't tell how much cum she's swallowed when she's finally told she's earned to give birth. Her pants are taken off. Before she can push, she feels a hand against the head stretching her pussy wide. They want to see her give birth, they explain - and push the head back into her body. She screams in pain and frustration and they laugh at her.
The labour has lasted so long she no longer has strength to push. They berate her, slap her face and stomach, tell her to push. She tries, but her body is weak. They start pushing on her stomach as she pushes and she screams, delirious from pain. They press hard, and eventually, the baby crowns.
They move her so that she's on her knees and her face pressed on the floor. One of them presses their thumb into her ass. She sobs when they tell her they'll teach her to get used to the sensation. They let her give birth like that. As soon as the afterbirth comes, they start fucking her. She's only half conscious as a cock after cock is shoved into her bleeding cunt and she's filled with cum. Now, they say, when her womb is still open for them.
They make sure to breed her again, this time with their child.