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A new IUD available in a few countries uses a synthetic hormone to achieve a high rate
of long-acting contraception, typically with less bleeding than any other type of
currently available IUD.
 Menstrual bleeding is reduced in all women who
use the levonorgestrel (LNg)-releasing device, in some by so much that they hardly bleed
at all. The LNg IUD can be inserted early in a woman's reproductive life and its
contraceptive effect is reversible. The device combines the high efficacy of modern
hormonal contraceptives, such as injectables, with the convenience of intra-uterine
contraception.
The device is available in Europe and Singapore. Since it has not yet been approved by the
U.S. Food and Drug Administration for use in the United States, it is not available
through the U.S. Agency for International Development, which provides contraceptive
commodities to many developing countries. The LNg IUD, also known as the LNg-20 IUD
because it releases 20 micrograms of levonorgestrel daily, is manufactured by Leiras
Pharmaceuticals in Turku, Finland. It received approval for use in Finland in 1990 and in
Sweden, Norway and Denmark in 1992, where it is marketed under the brand name Levonova,
and in Singapore and the United Kingdom in 1995, where it is sold as Mirena.
Worldwide, one other hormonal IUD is on the market, and it is available only in the United
States. Progestasert, made by ALZA Corporation in Palo Alto, CA, USA, uses the natural
hormone progesterone, but is approved for only one year of use. Since it was first
marketed in 1976, demand has been limited.
A related approach, the intra-cervical device (ICD), is in the early stages of development
at the University of Helsinki, Finland. This product also contains LNg, but has a slightly
smaller size than the LNg-20 IUD and is placed in the cervical canal instead of the
uterus. Because of this, insertion may be easier and may require less training.
Five years of use
The LNg IUD is currently approved for five years of use in countries where it is
available and indications are promising that it may be highly effective for longer. It is
shaped like a copper-bearing Nova T IUD, but contains no copper. Instead, the vertical
portion of the "T" bears a small rubber sleeve containing 52 milligrams of the
synthetic hormone levonorgestrel. Research shows it still contains 40 percent of its
original steroid load after five years. Because of its long-acting effect, some experts
consider the LNg IUD an alternative to surgical female sterilization, the most widely-used
modern contraceptive method.
Finnish researchers compared the opinions of 61 LNg IUD users with 44 users of the
copper-bearing Nova T at several clinics in Helsinki. About half (48 percent) of the LNg
users expressed high satisfaction compared with 23 percent of women using the copper IUD.1 The high level of satisfaction may be due to the LNg IUD's
reduction of menstrual bleeding and its high efficacy rates, even among young women.
Combined results from three international trials and one national trial involving 7,393
women in 17 countries show the LNg-20 IUD has a long-acting contraceptive effect, similar
to copper-bearing devices. The pregnancy rate for the LNg IUD was 0.2 per 100 users (two
pregnancies per 1,000 women during the first year), compared with 0.9 per 100 for the Nova
T and 0.4 per 100 for the Copper T 380.2
Unlike many other methods of contraception, the LNg IUD is highly effective among younger
users. Copper devices, oral contraceptives and other methods have higher failure rates for
women under 30, who are more prone to accidental pregnancy because they are more fecund
and have more frequent sexual intercourse than older women. In a study that tracked 338
LNg users under the age of 25 for five years, none became pregnant.3
Many users are attracted by the LNg IUD's ability to reduce menstrual bleeding and pain.
In contrast to copper IUDs, which tend to increase monthly blood loss by an additional 20
ml, the LNg IUD usually reduces or eliminates the normal monthly blood flow.4
This reduction is particularly important for women who suffer menorrhagia, or excessive
bleeding. By using the LNg IUD, these women can significantly reduce their bleeding. LNg
is so effective in reducing menses that it can be used as a therapeutic treatment for
menorrhagia and dysmenorrhea, excessive and painful bleeding.5
Levonorgestrel renders the endometrium unresponsive to estrogen, the body's natural
hormone responsible for growth of the uterine lining in preparation for pregnancy or
monthly shedding. Without this periodic growth, the lining remains thin and causes less
bleeding.6 The endometrium returns to its normal cycle soon
after the IUD is removed.
For most women, the first two to three months after LNg IUD insertion are accompanied by
lighter menstruation and some irregular spotting. Thereafter, up to 30 percent of LNg IUD
users become completely amenorrheic, with no spotting at all.7
A majority of women stop their periods but may continue to have occasional spotting. This
provides relief to women for whom menses are painful, inconvenient or excessive. In
cultures where amenorrhea may worry clients, counseling can reassure women that reduced
bleeding is not harmful and may be beneficial to their health. The manner of insertion can
affect the amount of bleeding. If the LNg IUD is placed correctly at the fundus of the
uterus, spotting is minimized.
Reduced blood loss, including amenorrhea, increases hemoglobin and iron levels. This
aspect of the LNg IUD may be advantageous among women with anemia.8
Given the appropriate counseling, women in many cultures may prefer amenorrhea.
Continuation rates increase when women are told to expect initial spotting, reduced
menses, and the possibility of amenorrhea.9 Women should be
informed that the reduction of bleeding is not harmful to their health.
Removal rates for bleeding disturbances appear to be about the same for LNg and
copper-releasing devices during the first year, at 8.7 and 7.5 percent respectively.10 After five years of use, removal rates for bleeding were
significantly lower among LNg users compared with copper IUD (Nova T) users. Heavy flow is
rare among LNg IUD users while it is the most common cause of menstrual-related removal
for copper IUD users. However, the LNg IUD did have more removals due to amenorrhea.11
PID, ectopic pregnancies
The reduced amount and duration of menstrual bleeding makes the genital tract less
hospitable to infection. In addition, levonorgestrel keeps the cervical mucus thick and
less penetrable by either sperm or bacteria. Consequently, pelvic inflammatory disease
(PID) may be less common among women using the LNg device, in comparison with users of
copper IUDs. A three-year study showed 0.5 cases of PID per 100 LNg IUD users, compared
with 2.0 per 100 copper IUD (Nova T) users.12 Other studies
show PID rates among different modern IUDs to be indistinguishable. The LNg device also
decreases the risk of myoma (benign uterine tumor).13 Rates
for ectopic pregnancy and expulsion appear to be the same for the Copper T 380 and LNg
IUD.14
Rare hormone-related side effects, such as acne, hair loss, weight change, headache,
breast tenderness and depression, are other reasons some women stop using the LNg IUD.
These infrequent side effects, however, account for only 2.7 removals per 100 users.15 In a multicenter study in Finland and Brazil involving 484
women, no change in body weight was detected among LNg users after one year.16
Persistent follicles, a phenomenon commonly associated with other progestin-only
contraceptives, such as Norplant, the injectable DMPA, and progestin-only pills, have also
been detected among LNg IUD users. While persistent follicles are more common among LNg
IUD users than among copper IUD users, the health effects are slight. These follicles
prompted only three removals from 1,821 women using LNg-20 IUDs for 12 months.17 Other studies have shown that this device has no detectable
effect on blood pressure, carbohydrate metabolism, and blood coagulation.18
Once the LNg-20 IUD is removed, fertility returns promptly, as it does with the Copper T
380. Ninety percent of women using either device become pregnant within the first year
after their IUD is removed.19
Currently, the LNg IUD costs approximately U.S. $250 in Europe. A copper IUD costs about
U.S. $50 when bought in Europe, U.S. $280 when purchased in the United States.
-- Sarah Keller
Footnotes
- Shain R, Ratsula K, Toivonen J, et al. Acceptability of
an experimental intracervical device: Results of a study controlling for selection bias.
Contraception 1989;39(1):80.
- Luukkainen T. The levonorgestrel-releasing IUD. Br J Fam
Plann 1993;19(3):221-24.
- Luukkainen 1993, 221.
- Scholten P, van Eykeren M, Christiaens G, et al.
Menstrual blood loss with the levonorgestrel intrauterine device Nova T and Multiload CU
250 intrauterine devices. Thesis. Utrecht: University Hospital, 1989.
- Andersson JK, Rybo G. Levonorgestrel-releasing
intrauterine device in the treatment of menorrhagia. Br J Obstet Gynaecol
1990;97(8):690-94.
- Chi I-c, Farr G. The non-contraceptive effects of the
levonorgestrel-releasing intrauterine device. Adv Contracept 1994;10(4):272.
- Sivin I, Stern J. Health during prolonged use of
levonorgestrel 20 µg/d and the Copper TCu 380Ag intrauterine contraceptive devices: A
multicenter study. Fertil Steril 1994;61(1):72.
- Luukkainen T. Progestin-releasing intrauterine device.
Proceedings from the Fourth International Conference on IUDs. Ed. Bardin CW, Mishell DR.
(Newton, MA: Butterworth-Heinemann, 1994) 39.
- Luukkainen 1994, 36.
- Luukkainen T, Allonen H, Haukkamaa M, et al. Effective
contraception with the Levonorgestrel-releasing intrauterine device: 12-month report of a
European multicenter study. Contraception 1987;36(2):171.
- Andersson JK, Odlind V, Rybo G.
Levonorgestrel-releasing and copper-releasing (Nova T) IUDs during 5 years of use: A
randomized comparative trial. Obstet Gynecol 1994; 49(8):565.
- Toivonen J, Luukkainen T, Allonen H. Protective effect
of intrauterine release of levonorgestrel on pelvic infection: Three years' comparative
experience of levonorgestrel- and copper-releasing intrauterine devices. Obstet Gynecol
1991;77(2):261-64.
- Sivin, 74.
- Chi I-c. The TCu-380A (AG), MLCu375, and Nova-T IUDs
and the IUD daily releasing 20 µg Levonorgestrel: Four pillars of IUD contraception for
the nineties and beyond? Contraception 1993;47(4):340.
- Luukkainen 1987.
- Chi 1994, 280.
- Chi 1993, 340.
- Luukkainen 1993.
- Belhadj H, Sivin I, Díaz S, et al. Recovery of
fertility after use of the levonorgestrel 20 mcg/d or Copper T 380 Ag intrauterine device.
Contraception 1986;34(3):261-67.
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