Infertility was the inability for a lifeform to produce offspring.
Amy Pond was rendered infertile after her ordeal at Demons Run, after the birth of her first child, River Song. (TV: A Good Man Goes to War) This put great strain on her marriage to Rory Williams for a short time, nearly culminating in their divorce, before they reconsiled while on a trip to the Dalek Asylum with the Eleventh Doctor. (TV: Asylum of the Daleks) The couple later adopted a son, Anthony Williams. (PROSE: Summer Falls: Introduction, WC: Rory's Story)