Mechanism of action uterine contraceptive devices.

By S. TEJUJA Reproductive Biology Research Unit Department of Physiology All-India Institute of Medical Science, New Delhi. The increasing use of the intrauterine contraceptive device (IUCD) as a method family planninghas demonstrated its popularity not only in India but also in other countries throughout theworld. This has, in its turn simulated considerable research on its biological effects both in experimental animals as well as in the human. It has been shown that these devices have an antifertility effect in practically all the species that have been tested, although the stage of reproductiveprocess influenced differs from species to species. These differences noted in its mode of action may be as a result of difference in the anatomial conguration among various species, or asa result of marked variation in size shape and composition of the devices used. In the human, IUeD'S are generally composed of stainless steel or mixture of polythylene and barium sulphate. Various shapes that have been used are loops, coils, bows, rings of sizes which fill the uterine cavity without applying undue lateral pressure to the uterine walls. In the large domestic animals spirals of polythylene have been used. In the rodents and rabbits, threads of silk or nylon were used in earlier experimental work.