Sperm, also known as semen, ejaculation, cum, jizz, spunk, spooge, dickjuice and "yoghurt" was the male biological component of sexual reproduction.
Whilst on the Worldsphere, Dep had sex with Chris Cwej and impregnated herself with his sperm. (PROSE: The Also People)
By the 21st century, humans did not need to have sex to reproduce — males donated sperm to centres, and it was injected into females by syringe. (TV: Out of Time) Carys Fletcher worked at the Conway Clinic, one such sperm donation facility. (TV: Day One)