That's a very unattractive metaphor. I assume the expression relates to Dyson-brand vacuum cleaners and the idea that pregnancy termination involves removing the fetus through suction, so vacuum it out would probably express the same idea.
One of my daughters in an obstetrician, so I can bring a little technical expertise to this discssion.
Vacuum is commonly used these days to help in difficult deliveries. It is considered superior to caesarian section because it is less invasive and risky, obviously. According to my source, vacuum is now considered superior to the use of forceps too, but only because today's residents are not motivated to learn the use of forceps. We suspect this is because US health insurance systems pay much better for caesarian than for forceps delivery.
The use of the brand name Dyson, a manufacturer of home vacuum cleaners, remains a small mystery to me.