Abstract: A method of automated prolonged slow release artificial intrauterine insemination is disclosed wherein motile sperm are introduced into the uterus in a programmed, organized and metered pattern over an extended period of time. A catheter is inserted into the uterine cavity and aliquots of sperm containing medium are injected at a rate of 10 to 20 mm/hr (approximately every 30 seconds) for between 4 to 6 hours. The motile sperm content of each aliquot is between 8,000 to 75,000. Preferably, the method is carried out with the use of a novel delivery device. The device of the present invention comprises a flexible catheter having a delivery channel, a first end attachable to a pumping means, and a second end (uterine end) adapted to pass through the cervix and into the uterine cavity. The catheter is provided with an inflatable balloon adjacent the second end. Upon inflation of the balloon, the catheter is immobilized in the vagina.