question:  Why did the Lieutenant go into labor early?
context: SPATIAL DELIVERY BY RANDALL GARRETT Women on space station assignments shouldn't get pregnant. One thousand seventy-five miles above the wrinkled surface of Earth, a woman was in pain. There, high in the emptiness of space, Space Station One swung in its orbit. Once every two hours, the artificial satellite looped completely around the planet, watching what went on below. Outside its bright steel hull was the silence of the interplanetary vacuum; inside, in the hospital ward, Lieutenant Alice Britton clutched at the sheets of her bed in pain, then relaxed as it faded away. Major Banes was all smiles and cheer now, but he hadn't been that way five months ago. Your husband may be the finest rocket jockey in the Space Service, but that doesn't give him the right to come blasting up here on a supply rocket just to get you pregnant!" "But that was two and a half months ago! "Lieutenant Britton, it is my personal opinion that you need your head examined, and not by a general practitioner, either! The terrible pressure of a rocket landing would increase her effective body weight to nearly half a ton; an adult human being couldn't take that sort of punishment for long, much less the tiny life that was growing within her. Her pregnancy had never made her uncomfortable; the slow rotation of the wheel-shaped station about its axis gave an effective gravity at the rim only half that of Earth's surface, and the closer to the hub she went, the less her weight became. According to the major, the baby was due sometime around the first of September. And then, only half an hour ago, a meteor had hit the radar room. The depressurization hadn't hurt her too much, but the shock had been enough to start labor. It will be at least three hours before they can get a ship up here. Major Banes was in the Communications Center a full five minutes before the coastline of California appeared on the curved horizon of the globe beneath them.
output:  A slight depressurization in the space station shocked her body into labor.
options:  A slight depressurization in the space station shocked her body into labor.  Major Banes induced labor early because the baby was unusually large.  The stress of living in outer space caused her body to go into pre-term labor.  An asteroid crashed into the space station causing it to jerk unexpectedly. The Lieutenant fell and her water broke.