I found this tonight have a look,interesting info


taken from


http://www.contraceptiononline.org/slides/slide01.cfm?q=levonorgestrel-releas...



Slide Title:
WHO Medical Eligibility Criteria for the IUD Among Women With Certain Medical Conditions (Cont’d)

Talk Title:
Intrauterine Contraceptives

Related Terms:
copper-releasing IUD | diabetes | epilepsy | levonorgestrel-releasing IUD | migraine | obesity | risk | thrombogenic mutation | thyroid disorder | viral hepatitis | WHO Medical Eligibility Criteria for IUD Use

Notes:
The World Health Organization (WHO) Medical Eligibility Criteria for Contraceptive Use provides guidance to healthcare providers on safety of contraceptive methods for a wide range of health conditions. The WHO levels of risk are: category 1 = there are no restrictions for using the method; category 2 = the benefits of using the method generally outweigh the theoretical or proven risk; category 3 = the risks of using the method usually outweigh the benefits; and category 4 = there are unacceptable health risks associated with using the method for a patient with the indicated condition.




As shown in this table, there are a number of health problems that do not preclude the use of an IUD. The following information is taken from the WHO Medical Eligibility Criteria for IUD Use:




Progestogens are also thought to increase the risk for thromboses, although this increase is substantially less with a levonorgestrel-releasing IUD than with combined oral contraceptives. Among women with known thrombogenic mutations, using an IUD is considered to provide benefits that generally outweigh any theoretical or proven risk (risk category 2).

Aura is a specific focal neurologic symptom. For more information on this and other diagnostic criteria, see the International Classification of Headache Disorders, 2nd Edition, published by the Headache Classification Subcommittee of the International Headache Society.




Women who have any type of diabetes can use a levonorgestrel-releasing IUD (risk category 2), but it is unclear whether the amount of levonorgestrel released by the LNG-IUS may slightly influence carbohydrate and lipid metabolism. Some progestogens may increase the risk of thrombosis in women with diabetes, although this increase is substantially less than that for combined oral contraceptives. There are no restrictions for IUD use by women who have a history of gestational diabetes (category 1).




The progestin-only contraceptives are metabolized by the liver and their use may adversely affect women whose liver function is compromised, for example, by active viral hepatitis. Although there is concern about the effect of levonorgestrel-releasing IUDs on the liver function of these women, the effects of this IUD are less than those experienced with combined oral contraceptive.


References:
World Health Organization. Intrauterine devices. In: Medical Eligibility Criteria for Contraceptive Use. 3rd ed. Geneva: World Health Organization; 2004. Available at:
http://www.who.int/reproductive-health/publications/mec/iuds.html.
Accessed January 14, 2007.
Headache Classification Subcommittee of the International Headache Society. The International Classification of Headache Disorders, 2nd Edition. Cephalalgia. 2004;24(Suppl 1):1-150.