Action Of Intrauterine Contraceptive Devices Research Articles

The intrauterine contraceptive device: An often-forgotten and maligned method of contraception

Although 90% of women at risk for unintended pregnancy in the United States use contraception, <1% of these women use the intrauterine contraceptive device. The mechanism of action of intrauterine contraceptive devices has been controversial, but several studies suggest that interference with sperm migration or function and with fertilization may be the most likely mechanisms. More important, there is lack of compelling evidence that the intrauterine contraceptive device acts as an abortifacient. The risk for pelvic inflammatory disease among users now appears to be extremely low, primarily as a result of better selection of candidates. A levonorgestrel-releasing intrauterine contraceptive device may offer some new therapeutic approaches for the treatment of certain gynecologic disorders. Although women who are not at risk for pelvic inflammatory disease or sexually transmitted diseases are appropriate candidates for the intrauterine contraceptive device, it appears that use can be expanded to selected nulliparous women and women with certain medical conditions. (Am J Obstet Gynecol 1999;181:1-5.)

Mechanism of action of intrauterine contraceptive devices and its relation to informed consent

The purposes of this review are to evaluate the available evidence for the mechanisms of action of copper-impregnated intrauterine contraceptive devices and to describe the informed consent consequences of those mechanisms. The medical literature was reviewed with the use of the Bioethics and Medline databases (1966 to present). Reports that supported or refuted the two major postulated mechanisms (interference with implantation of the fertilized ovum or spermicidal inhibition of fertilization) were assessed for their relative strength and support for the exclusivity of one or the other mechanism. The analysis of the evidence strongly suggests that the contraceptive effectiveness of intrauterine contraceptive devices is achieved by both a prefertilization spermicidal action and a postfertilization inhibition of uterine implantation. Patient informed consent for intrauterine contraceptive device insertion should include a discussion of these mechanisms of actions so as to avoid their use in patients with moral objections to postfertilization contraception.(Am J Obstet Gynecol 1997;176:503-6.)

"New Insights on the Mode of Action of Intrauterine Contraceptive Devices in Women."

To gain a better understanding of the mechanism of action of intrauterine devices (IUDs), a search was made for ova in the genital tracts of 115 women using no contraception and of 56 women using IUDs, all of whom volunteered for study in conjunction with surgical sterilization. Ova were recovered from tubal flushings between 48 and 120 hours after the midcycle peak of luteinizing hormone in 39% of the IUD users compared with 56% of women in the control group (0.05

New insights on the mode of action of intrauterine contraceptive devices in women

To gain a better understanding of the mechanism of action of intrauterine devices (IUDs), a search was made for ova in the genital tracts of 115 women using no contraception and of 56 women using IUDs, all of whom volunteered for study in conjunction with surgical sterilization. Ova were recovered from tubal flushings between 48 and 120 hours after the midcycle peak of luteinizing hormone in 39% of the IUD users compared with 56% of women in the control group (0.05 less than P less than 0.10). This suggests an action of the IUD before the ovum reaches the uterus. Eggs with a microscopic appearance consistent with fertilization were recovered from the fallopian tubes of half of the women using no contraception who had intercourse within the fertile period of the reproductive cycle and from whom ova were recovered. In contrast (P less than 0.01), no eggs with this appearance were recovered in IUD users who had intercourse within the fertile period. No ova were recovered from the body of the uterus of any of the IUD users. Fertilized ova are less likely to reach the uterine cavity containing an IUD. Thus, the principal mode of IUDs is by a method other than destruction of live embryos.

Possible role of mast cells in the mechanism of action of intrauterine contraceptive devices

The presence and number of mast cells and their relationship to other inflammatory cells were investigated in smears from intrauterine contraceptive devices. The results obtained suggest a possible role of mast cells in the mechanism of action of intrauterine contraceptive devices, on the basis of the peculiar known functions of mast cells.

BIOLOGIC MODE OF ACTION OF THE LIPPES LOOP IN INTRAUTERINE CONTRACEPTION

Abstract In investigating the true cause of the antifertility action of intrauterine contraceptive devices, 37 women who had been using Lippes loops over periods ranging from 24 hours to 36 months were studied. Combined clinical, cytologic, and histologic methods were employed. We estimated that there were many millions of macrophages in the endometrial cavity. This was a constant finding in all women using Lippes loops. From these observations, it was concluded that the Lippes loop attracts the macrophages, stimulating them to accumulate in the uterine cavity. It is not, therefore, the intrauterine device itself, but the macrophages which act as the contraceptive.

Biologic mode of action of the Lippes loop in intrauterine contraception

In investigating the true cause of the antifertility action of intrauterine contraceptive devices, 37 women who had been using Lippes loops over periods ranging from 24 hours to 36 months were studied. Combined clinical, cytologic, and histologic methods were employed. We estimated that there were many millions of macrophages in the endometrial cavity. This was a constant finding in all women using Lippes loops. From these observations, it was concluded that the Lippes loop attracts the macrophages, stimulating them to accumulate in the uterine cavity. It is not, therefore, the intrauterine device itself, but the macrophages which act as the contraceptive.

Ovarian Pregnancy and Intrauterine Device

THE MECHANISM of action of intrauterine contraceptive devices (IUCDs) is still unknown. The reported tubal pregnancies in association with IUCDs make it evident that, in these cases, the device did not interfere with fertilization of the ovum in the fallopian tube. The purpose of this report is to record the first case of ovarian pregnancy, to our knowledge, in association with an IUCD. Report of a Case In June 1966, a 29-year-old, white, gravida 6 para 5 had a Lippes loop inserted. She did well until Jan 3, 1967, when her menses lasted for ten days. Bleeding began again on Jan 15 and persisted for ten days, and for eight more days beginning Jan 30. She continued to bleed almost daily until the time of her admission on Feb 23. Four weeks prior to admission, pain developed in the right lower quadrant of the abdomen, and continued until surgery. Examination