Intrauterine device

From Wikipedia, the free encyclopedia

Intrauterine device
Photo of copper-T IUD
Background
B.C. type intra-uterine
First use 1909-1929
Failure rates (per year)
Perfect use 0.6%
Typical use 0.8%
Usage
Duration effect 5-10 years
Reversibility Immediate
User reminders Check thread position after each period
Clinic review Annually
Advantages
Benefits Unnecessary to take any daily action.
Emergency contraception if inserted within 5 days
Disadvantages
STD protection No
Periods May be heavier and more painful
Weight gain No
Risks Small risk of PID following insertion
This article is about contraceptive uterine devices that do not contain hormones. For hormonal uterine devices, see IntraUterine System.

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 method of reversible birth control.[1] 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 pregnancy is not desired. Depending on the type, a single IUD may be used for 5 to 10 years.

Contents

[edit] Types of IUDs

Availability of IUDs varies widely by country. Only one brand (Paragard T 380A), for example, is available in the United States, while seven brands (Flexi-T 300, Multi-Safe 375, Multi-Load Cu 375, Neo-Safe T380, Nova T 380, T-Safe 380A, and GyneFix - also called FlexiGard 330 or CuFix PP330) are available in Great Britain.[2] There are also hormonal devices that are placed in the uterus, one of which (Mirena) is approved for use in the U.S. Although U.S. organizations refer to all types of uterine devices as IUDs,[3][4] in the UK the term IUD only refers to inert or copper-containing devices, and the hormonal uterine devices are considered a separate method of contraception termed IntraUterine System or IUS.[2][5]

Most types of IUDs have a plastic T-shaped frame that is wrapped with copper and/or has copper bands. Some IUDs, such as the Nova T 380, also contain a small amount of silver.[2] The arms of the frame hold the IUD in place near the top of the uterus. The GyneFix does not have a T-shape, but rather is a loop that holds several copper tubes. The GyneFix is held in place by a suture to the fundus of the uterus.

All copper-containing IUDs have a number as part of their name. This is the surface area of copper (in square millimeters) the IUD provides.

[edit] Effectiveness and mechanism of contraception

All second-generation copper-T IUDs have failure rates of less than 1% per year, and cumulative 10-year failure rates of 2-6%.[6] The frameless GyneFix also has a failure rate of less than 1% per year.[7] Worldwide, older IUD models with lower effectiveness rates are no longer produced.[8]

The presence of a device in the uterus prompts 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.[9][10] Although the only experimentally demonstrated effect is spermicidal/ovicidal, it is believed the IUD also sometimes prevents the development of pre-implanted embryos.[11] Because many pro-life groups define fertilization as the beginning of pregnancy, this secondary effect has led some to label the IUD an abortifacient.

IUDs can not protect from STDs, and women using IUDs are at higher risk of developing pelvic inflammatory disease (PID), a serious complication of certain STDs.[12]

[edit] Contraindications

IUDs are not usually recommended for:[13]

  • Women at risk for certain sexually transmitted diseases (STDs) that can cause pelvic inflammatory disease (PID), or with or at risk for HIV. Presence of an IUD increases the risk of an STD progressing to PID, and increases the risk of a PID causing infertility.
  • Women who are anemic and experience heavy menstrual bleeding.
  • Women with benign trophoblast disease (molar pregnancy).
  • Women between 48 hours and four weeks postpartum. Perforation of the uterus is more likely to occur during insertion when the women is more than 48 hours but less than four weeks postpartum.[14]
  • Women who had a D&E abortion (second-trimester abortion) within the past four weeks.[15]
  • Women who have had a chemical abortion but have not yet had an ultrasound to confirm that the abortion was complete, or who have not yet had their first menstruation following the chemical abortion.[15]


IUDs may not be inserted in:[13]

  • Women who are pregnant.
  • Women with an active STD, or who have had PID within the past three months.
  • Women who have sepsis (infection) following childbirth or abortion.
  • Women with certain uterine abnormalities.
  • Women with pelvic tuberculosis.
  • Women with cervical, endometrial, or ovarian cancer awaiting treatment.
  • Women with malignant trophoblast disease.

Adverse reactions have been reported in women with metal allergies, both copper[16] and nickel.[17] An anecdotal report states that the wires in the ParaGard IUD are nickel wires plated with copper.[18]

While nulliparous women (women who have never given birth) are somewhat more likely to have side effects, this is not a contraindication for IUD use.

Some doctors prefer to insert the IUD during menstruation to verify that the woman is not pregnant at the time of insertion. However, IUDs may safely be inserted at any time during the menstrual cycle as long as it is reasonably certain the woman is not pregnant.[19] Insertion may be more comfortable if done midcycle, when the cervix is naturally dilated.[15]

[edit] Side effects and complications

Insertion of the IUD may introduce bacteria into the uterus. It is very important that the provider use proper infection-prevention techniques during insertion.[20] Antibiotics should be given before insertion to women at high risk for endocarditis (inflammation of the membrane lining the heart), but should not be used routinely.[21]

During the placement appointment, the cervix is dilated in order to sound (measure) the uterus and insert the IUD. Cervix dilation is uncomfortable and, for some women, painful. Doctors often advise women to take painkillers before the procedure to reduce discomfort, and some will use a local anaesthetic.

After IUD insertion, menstrual periods are often heavier, more painful, or both - especially for the first few months after they are inserted. On average, menstrual blood loss increases by 20-50% after insertion of a copper-T IUD; increased menstrual discomfort is the most common medical reason for IUD removal.[22]

Complications include expulsion and uterine perforation. Uterine perforation is generally caused by an inexperienced provider and is very rare. Expulsion is more common in younger women, women who have not had children, and when an IUD is inserted immediately after childbirth or abortion. Women should check the string of the IUD at least once per menstrual cycle to verify that it is still in place.

The string(s) may be felt by some men during intercourse. If this is problematic, the provider may cut the strings even with the cervix, so they cannot be felt. Shortening the strings does prevent the woman from checking for expulsion, however.

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. However, of pregnancies that do occur during IUD use, a higher than expected percentage (3-4%) are ectopic.[23]

Although the pregnancy rate during IUD use is very low (less than 1% per year), it is not a 100% effective method of birth control. If pregnancy does occur, presence of the IUD increases the risk of miscarriage, particularly during the second trimester. It also increases the risk of premature delivery. These increased risks end if the IUD is removed after pregnancy is discovered. Although the Dalkon Shield IUD was associated with septic abortions (infections associated with miscarriage), other brands of IUD are not. IUDs are also not associated with birth defects or other pregnancy complications.[24]

[edit] 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).

[edit] Popularity

The ParaGard T 380A was approved by the U.S. Food and Drug Administration (FDA) in 1984 and became available for use in 1988. It is still the only IUD approved for use in the U.S., and is used by 1.3% of women of reproductive age.[25]

Usage in other countries has been determined by surveys of married women of reproductive age. In this population, IUD use ranges from 5% in Belgium, to 18% in Scandinavia, 30% in Russia and China, and 40% in Kazakhstan.[26]

[edit] Hormonal uterine devices

Main article: IntraUterine System
Photo of LNG IUS
Enlarge
Photo of LNG IUS

Hormonal uterine devices do not increase bleeding as inert and copper-containing IUDs do. Rather, they reduce menstrual bleeding or prevent menstruation altogether, and can be used as a treatment for menorrhagia (heavy periods).

Although modern IntraUterine Systems use low doses of hormones, they still have the potential side effects associated with other hormonal contraceptives.

Progestasert was the first hormonal uterine device, developed in 1976[27] and manufactured until 2001.[28] It released progesterone, was replaced annually, and had a failure rate of 2% per year.[29]

As of 2006, the LNG-20 IUS - marketed as Mirena by Schering Health - is the only IntraUterine System available. First introduced in 1990, it releases levonorgestrel (a progestagen) and may be used for five years.

A lower-dose T-shaped IntraUterine System named Femilis is being developed by Contrel, a Belgian company. Contrel also manufactures the FibroPlant-LNG, a frameless IUS. FibroPlant is anchored to the fundus of the uterus as the GyneFix IUD is. Although a number of trials have shown positive results, FibroPlant is not yet commercially available.[30]

[edit] History

Presenters at a family planning conference told a tale of Arab traders inserting small stones into the uteruses of their camels to prevent pregnancy. Although the story has been repeated as truth, it has no basis in history and was meant only for entertainment purposes.[31]

Precursors to IUDs were first marketed in 1902. Developed from stem pessaries (where the stem held the pessary in place over the cervix), the 'stem' on these devices actually extended into the uterus itself. Also known as interuterine devices (because they occupied both the vagina and the uterus), they had high rates of infection and were condemned by the medical community.[32]

The first intrauterine device (contained entirely in the uterus) was described in a German publication in 1909, although the author appears to have never marketed his product.[33]

In 1929, Dr. Ernst Gräfenberg of Germany published a report on an IUD made of silk suture. He had found a 3% pregnancy rate among 1,100 women using his ring. In 1930, Dr. Gräfenberg reported a lower pregnancy rate of 1.6% among 600 women using an improved ring wrapped in silver wire. Unbeknownst to Dr. Gräfenberg, the silver wire was contaminated with 26% copper. Copper's role in increasing IUD efficacy would not be recognized until nearly 40 years later.

In 1934, Japanese physician Tenrei Ota developed a variation of the Gräfenberg ring that contained a supportive structure in the center. The addition of this central disc lowered the IUD's expulsion rate. These devices still had high rates of infection, and their use and development was further stifled by World War II politics: contraception was forbidden in both Nazi Germany and Axis-allied Japan. The Western world did not learn of the work by Gräfenberg and Ota until well after the war ended.[33]

The first plastic IUD, the Marguiles Coil or Marguiles Spiral, was introduced in 1958. This device was somewhat large, causing discomfort to a large proportion of women users, and had a hard plastic tail, causing discomfort to their male partners. The Lippes Loop, a slightly smaller device with a monofilament tail, was introduced in 1962 and gained in popularity over the Marguiles device.[32]

The stainless steel single-ring IUD was developed in the 1970s[34] and widely used in China because of low manufacturing costs. The Chinese government banned production of steel IUDs in 1993 due to high failure rates (up to 10% per year).[35][6]

Dr Howard Tatum, in the USA, conceived the plastic T-shaped IUD in 1968. Shortly thereafter Dr Jaime Zipper, in Chile, introduced the idea of adding copper to the devices to improve their contraceptive effectiveness.[32][36] It was found that copper-containing devices could be made in smaller sizes without compromising effectivesness, resulting in fewer side effects such as pain and bleeding.[6] T-shaped devices had lower rates of expulsion due to their greater similarity to the shape of the uterus.[33]

The Dalkon Shield (which had a multi-filiment string) was introduced in the United States in 1970. It was banned after being linked to 200,000 PID infections, more than 250 septic abortions, infertility, emergency hysterectomies, and 33 deaths.[citation needed]

Second-generation copper-T IUDs were also introduced in the 1970s. These devices had higher surface areas of copper, and for the first time consistently achieved effectiveness rates of greater than 99%. Worldwide today, with the exception of the new GyneFix, this is the only type of IUD available.[8]

[edit] See also

[edit] External links

[edit] References

  1. ^ What are the most widely used contraceptive methods across the world?. Births / Birth control. Institut national d'études démographiques (INED) (2006). Retrieved on 2006-11-16.
  2. ^ a b c Contraceptive coils (IUDs). NetDoctor.co.uk (2006). Retrieved on 2006-07-05.
  3. ^ (December 1995) "IUDs—An Update". Population Information Program, Center for Communication Programs 23 (5). Retrieved on 2006-07-09.
  4. ^ Progestasert IUD. Emory University: Department of Gynecology and Obstetrics (December 2005). Retrieved on 2006-07-16.
  5. ^ French, R, Van Vliet H, Cowan F, et al. (2004). "Hormonally impregnated intrauterine systems (IUSs) versus other forms of reversible contraceptives as effective methods of preventing pregnancy". Cochrane Database of Systematic Reviews (3). PMID 15266453.
  6. ^ a b c IUDs-An Update. Chapter 2.3: Effectiveness.
  7. ^ O'Brien, PA, Marfleet C (2005 Jan 25). "Frameless versus classical intrauterine device for contraception". Cochrane Database of Systematic Reviews (1). PMID.
  8. ^ a b IUDs—An Update. Chapter 1: Background.
  9. ^ Mechanisms of the Contraceptive Action of Hormonal Methods and Intrauterine Devices (IUDs). Family Health International (2006). Retrieved on 2006-07-05.
  10. ^ Keller, Sarah (Winter 1996, Vol. 16, No. 2). IUDs Block Fertilization. Network. Family Health International. Retrieved on 2006-07-05.
  11. ^ Stanford J, Mikolajczyk R (2002). "Mechanisms of action of intrauterine devices: update and estimation of postfertilization effects.". Am J Obstet Gynecol 187 (6): 1699-708. PMID 12501086.
  12. ^ IUDs-An Update. Chapter 5: Infection.
  13. ^ a b IUDs—An Update. Sidebar: WHO Scientific Group Updates Eligibility Guidelines for Copper IUDs.
  14. ^ IUDs—An Update. Chapter 3.3: Postpartum Insertion.
  15. ^ a b c Understanding IUDs. Planned Parenthood Federation of America (July 2005). Retrieved on 2006-07-22.
  16. ^ Pacilli L, Graffino W, Poggio A, Arrotta S (1981). "A case of allergy to a copper-medicated IUD. Etiopathogenetic and clinical aspects". Minerva Ginecol 33 (12): 1159-63. PMID 6460950.
  17. ^ Frentz G, Teilum D (1980). "Cutaneous eruptions and intrauterine contraceptive copper device.". Acta Derm Venereol 60 (1): 69-71. PMID 6153839.
    Merino G, Bailon R, Correu S (1991). "Comparative parameters of fertility regulation as related to STD / HIV infections. An overview.". Adv Contracept Deliv Syst 7 (2): 179-86. PMID 12284219.
  18. ^ ParaGard / Nickel connection??. birthcontrolled. LiveJournal (2006-08-13). Retrieved on 2006-10-11.
  19. ^ IUDs-An Update. Chapter 3: Insertion.
  20. ^ IUDs—An Update. Sidebar: Infection Prevention for IUD Insertion and Removal.
  21. ^ IUDs—An Update. Sidebar: Procedures for Providing IUDs.
  22. ^ IUDs-An Update. Chapter 2.5: Bleeding and Pain.
  23. ^ IUDs-An Update. Chapter 2.9:Ectopic Pregnancies.
  24. ^ IUDs-An Update. Chapter 2.8: Intrauterine Pregnancy.
  25. ^ National Survey of Family Growth Use of Contraception and Use of Family Planning Services in the United States: 1982-2002. Advance Data No. 350
  26. ^ IUDs—An Update. Worldwide Use - Developed Countries. Table 2: Worldwide Use of IUDs.
  27. ^ IUDs—An Update. Chapter 2: Types of IUDs.
  28. ^ Smith (pseudonym), Sydney (Saturday, March 08, 2003). Contraceptive Concerns. medpundit: Commentary on medical news by a practicing physician.. Retrieved on 2006-07-16.
  29. ^ Birth Control Options: The Progestasert Intrauterine Device (IUD). Wyoming Health Council (2004). Retrieved on 2006-07-16.
  30. ^ (April 2005) "New Contraceptive Choices". Population Reports, INFO Project, Center for Communication Programs M (19). Retrieved on 2006-07-14. Chapter 9: Intrauterine Devices.
  31. ^ A History of Birth Control Methods. Planned Parenthood (June 2002). Retrieved on 2006-07-05., which cites:
    Thomas, Patricia (1988-03-14). "Contraceptives". Medical World News 29 (5): 48.
  32. ^ a b c Lynch, Catherine M.. History of the IUD. Contraception Online. Baylor College of Medicine. Retrieved on 2006-07-09.
  33. ^ a b c (February 2000) "Evolution and Revolution: The Past, Present, and Future of Contraception". Contraception Online (Baylor College of Medicine) 10 (6).
  34. ^ Bradley, Jeff (August 1998). Ultrasound Interactive Case Study: Ring IUD. OBGYN.net. Retrieved on 2006-07-09. (Has pictures of various IUD designs.)
  35. ^ Kaufman, J. (1993 May-Jun). "The cost of IUD failure in China". Studies In Family Planning 24 (3): 194-6. PMID 8351700.
  36. ^ Van Kets, H.E.; Editors C. Coll Capdevila, L. Iglesias Cortit and G. Creatsas (1997). Importance of intrauterine contraception. Contraception Today, Proceedings of the 4th Congress of the European Society of Contraception 112-116. The Parthenon Publishing Group. Retrieved on 2006-07-09. (Has pictures of many IUD designs, both historic and modern.)



Birth control edit
Avoidance: Celibacy, Abstinence
Barrier: Condom, Diaphragm, Shield, Cap, Sponge, Spermicide
Natural: Coitus interruptus, Fertility awareness, BBT, Billings, Creighton, Rhythm Method, Lactational
Hormonal: Combined: COCP pill, Patch, Nuvaring • Progesterone only: POP mini-pill, Depo Provera, Norplant, Implanon
Anti-estrogen: Ormeloxifene (a.k.a. Centchroman)
Intra-uterine: IUD, IUS (progesterone)
Post-intercourse: Emergency contraception • Abortion: Surgical, Chemical, Herbal/Drug
Sterilization: Tubal ligation, Vasectomy, Essure
Retrieved from "http://en.wikipedia.org../../../i/n/t/Intrauterine_device.html"