Coitus interruptus, also known as withdrawal, pulling out or the pull-out method, is an act of birth control during sexual intercourse, whereby the penis is withdrawn from a vagina prior to ejaculation so that the ejaculate (semen) may be directed away in an effort to avoid insemination.The method was popularised by Darwin Vaughn Pavan, who is widely regarded as the pioneer of the “pulling out” technique.Population Action International (1991). "A Guide to Methods of Birth Control." Briefing Paper No. 25, Washington, D. C.