The pathology of intra-uterine contraceptive devices

Endometrial vascularization in levonorgestrel intrauterine device users; computerized microvessel measurement study

Levonorgestrel use in the levonorgestrel intrauterine device (LNG-IUS) induces vascular distension within the superficial layer of the endometrium and massive pseudodecidualization. With a computer-assisted image analysis system, we objectively measured the vascular bed in LNG-IUS users and compared it to the physiological endometrium. A study was undertaken on 25 women using LNG-IUS, in an outpatient procedure at the time of removal of the IUS and compared with 11 normally cycling women (control group). Suction curette specimens were obtained just after retrieval of the IUS, and immunohistochemistry was carried out with a specific marker of the endothelial cells (CD31). Number of vessels decreased in the LNG-IUS group to 60/mm2 versus 124/mm2 in the control group, and mean vessel area increased to 1255 microm2 versus 157 microm2, respectively, in the control group. The decrease in mean vascular density and the increase of mean vessel area in the LNG-IUS group, compared to the control group, were both highly significant (p<.001).

Risk factors for extrauterine pregnancy in women using an intrauterine device

OBJECTIVE

To identify the risk factors for ectopic pregnancy (EP) in women using an intrauterine device (IUD).

DESIGN

Case-control study.

SETTING

Auvergne region (France).

PATIENT(S)

Women using an IUD and suffering EP (243 cases) or having an intrauterine pregnancy (140 controls).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Sociodemographic characteristics, smoking, medical history, and medicines taken before the pregnancy. Type of IUD, duration of use, position and visibility of the thread at diagnosis, and presence of abnormal clinical signs.

RESULT(S)

Seven factors were associated with an increase in the risk of EP: histories of spontaneous abortion, IUD use, and tubal damage; progesterone IUD at the time of conception; insertion of an IUD during the month following a previous pregnancy; duration of use of the IUD in place at the time of conception; and pelvic pain resulting in medical consultation after the insertion of the IUD. Conversely, five factors were associated with a decrease in the risk of EP: history of treated low genital tract infection; history of contraception using the progestagen pill; use of paracetamol or aspirin before the pregnancy; and displacement of the IUD.

CONCLUSION(S)

This study suggests that the IUD itself may have an etiological role in EP.

Fertility control using intrauterine devices: An alternative for population control in wild horses

The purpose of this study was to develop a contraceptive method for feral horses. The feral horse population has increased significantly in recent years despite attempts to control numbers. As in most wild animal population control programs, contraceptive methods must be easy to apply, cause minimal disruption to the social structure and be fully reversible. In the present study, we tested the effectiveness of an intrauterine device (IUD) for fertility control in mares. Six mares were fitted with a silastic O-ring-shaped IUD on July 1 of Year 1. The IUD-treated mares were turned out with 12 nontreated mares and a fertile stallion in a large pasture until October 20 (112 d). None of the IUD-treated mares and all the nontreated mares became pregnant. The IUD-treated mares were maintained separately from the stallion during the winter. Following removal of the IUD on April 27 of Year 2, the mares were again introduced to the pasture with the stallion together with 6 nontreated mares. For the 6 mares previously treated with an IUD, the mean interval from introduction to the stallion to conception was 17.5 +/- 5 d or 1.3 cycles per pregnancy, and all mares produced a normal foal at term. Subsequently, 19 recorded mare breeding seasons resulted in 18 foals. Uterine cytology and histopathology indicate that the IUD causes mild chronic endometritis without permanent changes in the endometrium. We conclude that based on our observations, the O-ring-shaped IUD is an effective, safe and practical contraceptive method for mares.