Progenation was a method of artificial reproduction from a single organism wherein one parent is biological mother and father. It involved taking a sample of diploid cells, splitting them into haploids, recombining them in a different arrangement and growing the result into an offspring.
During the Human-Hath War on the planet Messaline, both the Human and Hath factions used progenation machines to generate their armies. The progenation machines used in that conflict were able to create and grow a new offspring in a matter of moments. Jenny, the Tenth Doctor's daughter, was born using this method. (TV: The Doctor's Daughter)
Behind the scenes[]
The mark left on the Doctor's hand was identical in shape, size, and location to the scar on the back of the Empty Child's hand.