Designer baby
The technique is as follows. A sample of the father's sperm is spun in a centrifuge. Sperms carrying an X-chromosome are heavier than sperm carrying a Y-chromosome. The male-causing sperm end up at the top of the plug of sperm in the test-tube. Sperm from the top of the tube are inserted into the mother. This greatly increases the chance of the mother conceiving a male child.