T. Luukkainen et J. Toivonen, LEVONORGESTREL-RELEASING IUD AS A METHOD OF CONTRACEPTION WITH THERAPEUTIC PROPERTIES, Contraception, 52(5), 1995, pp. 269-276
The levonorgestrel-releasing intrauterine device LNg IUD is a new cont
raceptive method that combines the advantages of both hormonal and int
rauterine contraception. It gives users non-contraceptive health benef
its and can also be used as an effective therapy for menorrhagia. The
local release of LNg within the endometrial cavity results in strong s
uppression of endometrial growth as the endometrium becomes insensitiv
e to ovarian estradiol. The endometrial suppression is the reason for
a significant reduction of menstrual blood loss or amenorrhea, and for
the disappearance of dysmenorrhea. The bleeding pattern during the us
e of the LNg IUD is characterized by reduction,of the blood loss and i
n the number of bleeding days per cycle. During the first two to three
months of use, however, irregular spotting is common. The removal of
the device results in a quick return of menstrual bleeding and fertili
ty. The failure rate of copper-releasing IUDs, as with other methods o
f fertility regulation, is higher in young women and decreases with ag
e. The LNg IUD, on the other hand, has the same low pregnancy rate in
every age group of the users. The LNg IUD also gives protection agains
t ectopic pregnancy and pelvic inflammatory disease and, by reducing m
enstrual blood loss, increases the body iron stores. The LNg IUD can b
e used to effectively treat menorrhagia. This has been demonstrated in
studies with quantitative determination of menstrual blood loss. Duri
ng the first year of use, the LNg IUD reduced menstrual blood loss by
90% from pretreatment levels. Comparative clinical trials with the LNg
IUD cover more than 10,000 women-years of follow-up during use over f
ive to seven years. The Pearl pregnancy rate in studies has been 0.0-0
.2 per 100 women-years. The overall ectopic Pearl pregnancy rate is 0.
02 per 100 woman-years. The LNg IUD is marketed in Denmark; Finland, N
orway, Sweden and in the United Kingdom.