 Why do they need an incubator?
Once every two hours, the artificial satellite looped completely around the planet, watching what went on below. 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. "Something wrong, doctor?" "Incubator," he said, without taking his eyes off the clock. "Incubator. We can't deliver a seven-month preemie without an incubator."
 The baby is two months early.
 The baby is one month early.  The baby is three months early.  The baby is two months early.  The baby is four months early.