Intrauterine device

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An intrauterine device (intra meaning within, and uterine meaning of the uterus) is a birth control device also known as an IUD or a coil (this colloquialism is based on the coil-shaped design of early IUDs). It is a device placed in the uterus and is the world's most widely used and inexpensive method of reversible birth control. The device has to be fitted inside or removed from the uterus by a doctor or qualified medical practitioner. It remains in place the entire time contraception is desired. Depending on the type, IUDs can usually remain effective for 2, 5 or 10 years.

1 Types of IUDs
2 Effectiveness
3 Side-effects
4 Common misconceptions about IUDs
5 Use as emergency contraception
6 See also
7 References
8 External links

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Types of IUDs

There are many types of IUDs worldwide, but only two types currently available in the United States: the copper-T intrauterine device (IUD) and the levonorgestrel-releasing intrauterine system (LNG IUS).

Image:IUDCPCopperT380A.gif The copper-T IUD is marketed as ParaGard T 380A by Barr Laboratories. It was approved by the Food and Drug Administration (FDA) in 1984 and became available for use in 1988. The device consists of a T-shaped polyethylene frame that is wound with copper wire around the vertical stem and has copper bands on the lateral arms. The ParaGard T 380A is approved for up to 10 years of use, although limited data support its effectiveness for at least 12 years.

Image:IUDCPMirena.gif The LNG IUS, marketed by Berlex Laboratories as Mirena, consists of a T-shaped polyethylene frame with a reservoir around the vertical stem that contains levonorgestrel. It was approved for use by the FDA in 2000. Initially the LNG IUS releases levonorgestrel at a rate of 20 µg per day.[1] This rate decreases to approximately half that rate by five years. It is indicated for up to five years of use, although limited data support its effectiveness for at least seven years.

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Effectiveness

The hormonal IUD is as effective as the contraceptive pill at preventing pregnancy; and the copper IUDs effectiveness ranges from 98% to over 99% depending on the brand. IUDs can not protect from STDs, and if an infection is caught while using an IUD it may be more likely to spread to the uterus.

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Side-effects

Copper IUDs may make menstrual periods heavier or more painful in some women, especially for the first few months after they are inserted, but modern types such as the GyneFix have been designed so that they usually do not affect periods (compare with IUS).

IUDs have remained unpopular in the USA since the Dalkon Shield IUD (which had a multi-filiment string) was banned after being linked to several deaths (it was thought the thick woven string hosted bacteria, which could spread to cause reproductive tract infections and occasionally fatalities). IUDs with monofiliment strings (including all modern IUDs) are much safer and complications are very rare. The number of deaths attributed to the Dalkon Shield were more likely due to lax sterilization procedures conducted on the IUD.Template:Fact

It is commonly believed IUDs cause a greater risk of an ectopic pregnancy. However, recent studies have shown that women with IUDs actually have fewer ectopic pregnancies than women using no contraception. However, in the rare cases that a pregnancy occurs with an IUD in place that is not removed, it is more likely to be ectopic.

IUDs are not recommended for women who are suffering from a pelvic inflammatory disease.

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Common misconceptions about IUDs

Template:Citation needed

Primary method of pregnancy prevention is abortifacient
IUDs work by prompting the release of leukocytes and prostaglandins by the endometrium. These substances are hostile to both sperm and eggs; the presence of copper increases this spermicidal effect. Although the only experimentally demonstrated effect is spermicidal/ovicidal, it is possible the IUD may rarely prevent the development of embryos<ref>Family Health International "Mechanisms of the Contraceptive Action of Hormonal Methods and Intrauterine Devices (IUDs)" Report</ref><ref>IUDs Block Fertilization. Family Health International. Network: Winter 1996, Vol. 16, No. 2.</ref>.

Causes ectopic pregnancies
The risk of ectopic pregnancy to a woman using an IUD is lower than the risk of ectopic pregnancy to a woman using no form of birth control. Of the tiny number of pregnancies that do occur, a higher than expected percentage is ectopic.

Causes pelvic inflammatory disease (PID)
PID is primarily caused by certain sexually transmitted diseases (STDs). While IUDs do not protect against STDs like barrier methods do, they also do not cause the infections. In women who have STDs, however, use of an IUD increases the risk the infection will progress to PID.

Needs to be removed for PID treatment
Causes infertility
As mentioned previously, certain women may increase their risk of PID or ectopic pregnancy by choosing to use an IUD. PID and ectopic pregnancy may adversely affect a woman's fertility. However, women not at risk of PID will not increase their risk of infertility by using an IUD.

Cannot be used in nulliparous women
Needs to be removed if actinomyces-like organisms are seen on Pap test

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Use as emergency contraception

Intrauterine devices can be used as emergency contraception to prevent pregnancy up to 5 days after unprotected sexual intercourse, or sexual intercourse during which the primary contraception is believed to have failed (e.g. a condom was used, but it broke). Insertion of a copper-T IUD as emergency contraception is more than 99% effective, making it more effective than Emergency contraceptive pills (ECP or 'morning-after pill').

IUDs may also be used where ECPs are less appropriate:

ECP are contraindicated in those with severe liver disease or the very rare condition of porphyria.
ECP are currently licensed for only 3 days (72 hours) after coitus
ECP will be ineffective if currently suffering from diarrhea or vomiting
The effectiveness of ECP may be reduced by the herbal preparation St John's wort and enzyme-inducing drugs (e.g. antiepileptics or rifampicin).

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