Recommendations for Contraceptive Use
		Levonorgestrel-Releasing IUDs

Lng - IUD: Levonorgestrel-20 IUDs

The levonorgestrel-20 IUD (LNg IUD) releases about 20 micrograms of levonorgestrel into the uterine cavity daily, leading to:

1. highly effective contraception rates (comparable to female sterilization) for five to seven years;
2. decreased blood loss compared to other IUDs, and decreased blood loss for women with a history of heavy menses (although the mean number of bleeding days is higher than normal for the first few months, it becomes lower than normal by six to eight months of using the levonorgestrel IUD, with improvement in anemia due to menstrual blood loss);
3. improvement in dysmenorrhea in most women;
4. decreased risk for ectopic pregnancy; and
5. possible use as the progestin necessary for a menopausal woman on estrogen replacement therapy.

The levonorgestrel IUD works in at least three ways:

• by causing a thick cervical mucus which inhibits the passage of sperm through the cervical canal;
• by causing anovulation in about 25% women; and
• by causing high levonorgestrel levels in the uterine cavity, which suppress estradiol receptorsand produce an atrophic endometrium, and inhibit passage of sperm through the uterine cavity.

Serum levonorgestrel levels are low, thus reports of hormonal side effects are few; no difference between LNg IUDs versus other IUDs has been reported concerning weight, blood pressure or lipid or carbohydrate metabolism. Because pituitary suppression is not strong, the LNg IUD does not cause a hypoestrogenic state.

Citations:

1. Luukkainen T, Toivonen J. Levonorgestrel-releasing IUD as a method of contraception with therapeutic properties. Contraception 1995;52:269-76.
2. Andersson K, Odlind V, Rybo G. Levonorgestrel-releasing and copper-releasing (Nova T) IUDs during five years of use: a randomized comparative trial. Contraception 1994:49:56-72.
3. Intrauterine progestagen for effective contraception. IPPF Medical Bulletin 1992;26(4).
4. Hatcher RA. The levonorgestrel-20 IUD (monograph). Atlanta: Emory University 1997.

Any part of Recommendations for Updating Selected Practices in Contraceptive Use may be reproduced or adapted to meet local needs without prior permission from the TG/CWG Secretariat, provided the TG/CWG is acknowledged and the material is made available free of charge or at cost.