What is MIRENA ?? What is MIRENA
B.115
Intrauterine System
( Hormone
Containing Device to prevent Conception for Five years - Hormone bearing IUDs )
Overview:
Intrauterine contraceptive devices
or IUDs are materials which when introduced inside the womb (uterus) exert
contraceptive effect usually 3-12 years depending upon the material with which
the device impregnated. Intrauterine contraceptive device of ‘first generation’
were made only of plastic material. These were called insert IUDs or plastic
IUDs. Unlike present day copper releasing IUDs there first generation IUD did
not contain only active metal or hormonal agent which could exert added
contraceptive efficacy. There insert IUDs exerted their contraceptive efficacy
mainly by mechanical limitation inside womb. None these less these IUDs were
popular in the decodes of sixties and early seventies but due to their poor
contraceptive efficacy and increased side effects (bleeding and pelvic pain)
these insert IUD ere replaces by copper
containing IUDs which soon because popular. There are called second generation IUDs. In fact copper
containing IUDs which was introduced the late seventies is still the most
popular IUD.
There are some women who are
unsuitable for copper containing IUDs. These women usually have some gynaecological
complaints or disease e.g. menorrhogia, small myoma (tumors of womb) or endrometrioss
etc). Such women will be benefited by fitting with an IUD which contain
progesterone hormone. This progesterone is
called first generation IUDs. The progesterone hormone used in the device
is Levonorgestrel the abbreviation of
which LNG and the contraceptive
device is called ‘LNG-IUS’.
In view of the fact that such
hormone containing IUDs release progesterone inside the womb these devices will
take care of existing gynecological disease in addition exerting contraceptive
action. Thus women suffering from above quoted gynaecological diseases will
achieve dual benefit of ‘disease control’
as well as ‘contraception’ by the use
of ‘LNG IUS’. But readers should not
be impression that these IUS are meant for contraception of diseased women
only. LNG IUS device can certainly be used in healthy women too particularly
where copper containing devices are not chosen by the acceptor.
Composition:
Like copper bearing IUDs the frame
of IUS device is also made of a light, T-Shaped plastic frame with the stem for
the T a bit thicker than IUDs. It is stem which contains a tiny storage system
of contraceptive hormone levonorgestrel.
The device is 32 mm in length and 4.8 mm in diameter. Like copper being devices
it is also impregnated with barium sulphate which makes it radio-opaque. So
that device became visible by ordinary X-Ray.
In fact the hormone reservoir
designed as a sleeve of 52mg of levonorgestrel mixed with polydimethyl siloxane elastomer This sleeve in turn surrounds the
vertical stem and is covered on its outer as feet by a membrane, which regulates
the intrauterine release of progesterone hormone from reservoir. There is
release of 20 mcg per 24 hours with passage of time. The release rate slowly
decreases to about 15 mcg per day with the fifth year of use and to about 12
mcg per day at the end 7 years.
Brand Name:
The levonorgestrel-releasing
intrauterine system (LNG-IUS) ‘Mirena’ or
‘Leva Nova’. This device was
approved in the country of origin, Finland; in 1990 FDA of US issued its
approval in the year 2000. It is manufactured by Leiras OY (Turku, Finland),
and it is currently on the market for contraceptive use in 88 countries
including India. In some country have, it is viewed chiefly for treatment of menorrhagia and as
progestin component in postmenopausal
hormone replacement therapy.
Mode of Action:
1)
Progesterone hormone released from the device impairs
upward migration of sperm by increasing cervical mucus viscosity.
2)
Progesterone also causes damage to sperms by causing
changes in enzyme present in the womb which facilitates sperm transport from
womb to egg-carrying tubes (fallopian tubes).
3)
Additionally LNG-IUS acts locally on the endometrium
(inner lining of womb) and cause profound changes the future bed of embryo so
that fertilized ova cannot get embedded. Thus in case occasionally union
between sperm and ova occur in the usual site i.e. egg carrying tube (fallopian
tube). When fertilized ova arrived at womb for nidation or (implantation) it forces
adverse environment in womb and unable to get embedded.
In summary
LNG-IUS either immobilizes sperms or inhibits sperm changes necessary for
fertilization. It is not an abortificient even if one considers life beings as
soon as fertilization occurs.
Unlike oral
pills IUS does not alter ovarian function. Because the amount of progesterone
absorbed from womb is minimal too modify normal functioning of ovaries. In fact
blood level of progesterone is well below 50% of minipill.
Intrauterine Dwelling Time Duration of Efficacy:
The device is currently approved for
a period of five years and removal should follow thereafter. If a woman desire
to continue contraceptive use, the device can be replaced after stipulated five
years and a new one fitted immediately after removal of the used device. But
recently evidence is fast accumulating that LNG-IUS retains its contraceptive
efficacy for seven years. Many trials have affirmed such claim.
There is evidence that the copper T 380A the
most popular brand of IUD has an effective life span of at least 12 years,
during which time the pregnancy rate remains very low.
Contraceptive Efficacy:
LNG-IUS (Mirena a Leva Nova) is a highly effective long-acting, reversible
contraceptive associated with a cumulative gross pregnancy rate of 0.0 to 0.5
for 4 or 5 years or with a pearl index (See Page ) of 0.0 to 0.2 for 7 years. In fact it is
so effective contraceptive that it is aptly called ‘reversible sterilization’.
STD Prevention:
Unlike male or female condom it does
not offer great protection against STI. Nevertheless LNG-IUS makes cervical
mucus thick and viscid. Thus it offers some resistance to upward progress of
organisms responsible for sexually transmitted infection (STI). As it does not
completely elements the possibility of acquiring STI. Therefore women who are
at risk of STI should be advised to use barrier contraceptive in addition (dual
protection).
Advantage as Contraceptives:
1) Highly effective: Failure rate of only 0-2 per 100 women years.
2)
Minimal
hormone related systemic side effects: The
hormone used in LNG-IUS is also used in most contraceptive pills including
minipills, and subdermal impalants (implanon).
In IUS however, a much lower does is released is body than when one takes
contraceptive pills. Further in case of IUS the hormone is deposited directly
in the lining of the womb, rather than in the blood stream. Hence progesterone
related side effects are less common with IUS.
3)
Makes
quality of life better in selected women: LNG-IUS has a definite edge over copper IUDs as it does
away with a number of problems associated with conventional IUDs. For instance
LNG-IUS causes light and less painful periods instead of excessive and painful
periods as with copper containing devices. It also reduces the amount and
duration of monthly period.
4)
Does not
alter the ovarian function and other natural hormones of body: The normal ovarian functions are not disturbed
neither the ovulation process is suppressed. This is because during use of the
LNG-IUS release of progesterone (Levonorgestrel) is limited to 20mcg 24 hours
amount yield to a of progesterone well plasma levels below 0.2mg/ml. The level
i.e. minimally required suppress ovulation.
In short LNG-IUS is a reversible method and unrelated to sexual: The best
features of this system is its high contraceptive efficacy, reduction in MBL
(menstrual blood loss), protection against ascending pelvic infection, and
minimal interference with ovarian function.
Limitations of contraceptives:
1)
High Cost:
It is good contraceptive for
women of developing world because the main non contraceptive benefit of LNG-IUS
is decrease in menstrual blood loss. This makes it as the best choice in women with anemia. It is well known that
both nutritional anemia and iron deficiency anemia are prevalent in women of
developing countries. But unfortunately, women of resource poor countries cannot
afford to high cost (Rupees six thousands in Indian currency to purchase
LNG-IUS contraceptive.
2)
Irregular
bleeding:
The other disadvantage is
irregular intermenstrual bleeding or amenorrhoea, neither of which are
acceptable in some cultures. Nevertheless continued use of the device greatly
diminishes menstrual irregularity. But to achieve this she has to use it at
least for six to eight months. Thus the first 4-6 months is crucial and great
patience is to be exercised. Continuation for first six months depends chiefly
on attitude of the client as well as on good counseling before and after the
IUS is fitted.
3)
Must be
fitted by a trained doctor:
Unlike copper IUDs this
specially designed IUS cannot be inserted by nurses or paramedical personnel.
This is simply because the stem of vertical limb of the device is much thicker
than most copper containing IUDs. So in most cases insertion will require some
dilatation of cervix preferably under short anesthesia. Thus fitting of IUS is
technically a bit difficult and only skilled persons can fit the device
properly.
4)
Spontaneous
expulsion:
This is rarely possible. In
such an unfortunate the women gets disappointed. She incurs some financial loss
too.
5)
Mal
position of IUS:
Through rare but this can
occur either during the insertion process or subsequently. It is noteworthy
that all IUDs and IUS are susceptible to undergo axial rotation while still
remaining inside the womb. This happens due to normal contraception and
relaxation of the musculature of womb.
6)
Not all
women are suitable for IUS: Role of Pre insertion hysteroscopic evaluation:
There are some women who has
some disease of womb e.g. inside partition, small tumors or polyps abutting the
inner cavity of womb. They are unsuitable for any intrauterine device. If LNG-IUS
is fitted without assessing cavity of womb then there remains faint possibility
of having persistently annoying side effects which may last for months together
such an event will impede the rising popularity of this IUS. To put in other
way not all women are fit for IUS and a pre-insertion evaluation by putting a
small endoscope inside the womb to access the inner walls or cavity of womb is
desirable though not essential. In fact
hystroscopic agreement is seldom practiced and this practice is possibly limited
to skeptic doctors only.
7)
Unlike copper bearing IUDs, LNG-IUS cannot be used as
postcoital emergency contraception.
8)
Pregnancy can follow if the device is expelled
spontaneously without the knowledge of the acceptor. This is again a rare
event. In summary, though the LNG-IUS may not replace copper intrauterine
devices due to its above quoted limitations and high costs, it could certainly
be used as a selective contraceptive
method for women who would benefit from it.
Non Contraceptive Benefits:
1)
Makes periods lighter from. Most copper IUDs make a
woman’s periods heavier, By contrast the LNG-IUS makes periods lighter than
usual. As a matter of fact there may be reduction of blood loss up to 94% after
3 months of use and after 12 months reduction may be up to 96%. Many clients
won’t believe this! Because of this, it is frequently used as a treatment for
heavy periods, even in women who don’t need contraception.
2)
Helpful in
many gynecological disease: LNG-IUS
ameliorates many gynecological diseases notably menorrhagia, (excessive flow
either in amount or duration), Dysmenorrhea (painful periods), endometriosis
(collection of menstrual blood in the tummy) and myoma (a common begin tumor of
womb).
3)
Improves premenstrual syndrome often called PMS.
4) Reduction of pelvic infection: The device appears to be protective against
pelvic inflammatory disease (PID) because of thickening effect on cervical
mucus thus preventing ascending infection. The incidence of pelvic infant’s
disease (PID) with LNG-IUS was found to be 0.8 per 100 woman years as compared
to 2.2 with copper IUD.
Ideal Candidate:
IUS is most appropriate
contraceptive method for women with menorrhagia (excessive menstrual bleeding)
or who prone to have to iron deficiency anemia. It is also suitable for women
who are candidates of Thalassaemaia or sickle cell disease. It is also suitable
for women suffering for Dysmenorrhea and or endometriosis. It is an ideal
contraceptive who are candidates with bleeding disorders or an anticoagulation
therapy. Breastfeeding women after 4-6 weeks postpartum can use it similarly it
can be used in women who are mentally retarded as a long term contraceptive. It
is safe for epileptics too. In short it is ideal for women who are mother of
one or two children and seek long term contraception but there should not be
any anatomical abnormality of womb i.e. cavity distortion.
Side effects and managing the problems:
I.
Menstrual
Bleeding Disorders: After
insertion of the LNG-IUS there is often a period of frequent irregular bleeding
or spotting during the first 2-3 months. This bleeding although small in
quantity may be very frequent or continuous in some women. These episodes can
cause considerable discomfort and inconvenience particularly to working women.
Interestingly though during first two to four months the number of
bleeding/spotting days are increased but the total volume of blood loss is
reduced compared with the woman’s normal menstruation. However if the woman is
dissatisfied with bleeding pattern then it can be managed by prescribing mefamic acid tablets (e.g. meftal tablet
500mg) 1 tab twice daily for 5 days.
She should be counseled that with increasing duration
of use she will develop amenorrhea. The rate of amenorrhea towards the end of
the 5 year period of use is around 25 percent. This is of considerable
advantage to women who are already anemic. Reassuringly the menstruation
returns in these amenorrhoeic women within 30 days of removal of IUS.
II.
Progesterone
related side effects:
Progesterone induced side effects/bloatedness e.g.
Breast tenderness, headache, acne and occasionally depression may occur. These
symptoms occur only in few women and pass off as the release rate of
progesterone from IUS decreases. 3) Spontaneous expulsion of the device. In
such an event the women will be unable to feel the thread in the upper part of
vagina. 4) Partial expulsion of the device is also rare. This should be
suspected if the women complain that she is feeling something hard in the mouth
of womb (cervix) or in the upper part of vagina. This may be associated with
pain and cramping. On examination HCP can visualize the lower part of the
vertical limb of the device in the cervix. Normally no part of the device
should be visible. Only the strings should be thus visible. Thus lengthen of
the strings or visualization of part of the device is indications that the
device has come down and is going to expel in no time. In such situation the
device should be removed and a new one fitted.
Wearing Signs:
1) Persistent irregular bleeding with pelvic pain: This may mean ‘disturbed uterine pregnancy’ while IUS still remaining inside or it
may be due to ectopic pregnancy (0.02
per 100 woman years.).
2)
Pelvic pain
alone: This
may be due to pregnancy occurring in fallopian tube (egg transport tube)
torsion of small cyst of ovary or acute P.I.D. (pelvic inflammatory disease).
Thought 10-12% of IUS users exhibit sonographic evidence of cyst formation but
torsion of such small cyst is very rare (1:2000).
3) Fever and pelvic Pain: This may be due to pelvic inflammatory
disease or acquiring fresh STI.
Contraindication:
Absolute contra-indications are a)
known or suspected pregnancy, b) current on recurrent pelvic inflammatory
disease, c) lower genital tract
infections particularly mucopurulent cervicitis. d) Postpartum or postabortal
endometritis i.e. infection of the womb. e) Cervical dysplasia f) known or
suspected carcinoma breast g) uterine or cervical malignancy h) leukaemia, i)
valvular diseases of heart j) severe
arterial disease.
Additionally women with known
disease of uterus where cavity distortion
has been substantiated by previous investigations (sonography or hystrography
or hystrocopy) then such women should be considered as unsuitable for both IUD
and IUS.
Relative contra-indications are
history of previous ectopic pregnancy, thromboembolic disease, history of
ovarian cyst. Unlike copper bearing devices LNG-IUS cannot be used as emergency
contraceptive.
Health Risks:
1) Pregnancy occurring all side the womb: The absolute ectopic pregnancy rate is extremely low with LNG-IUS. The
ectopic pregnancy rate of 0.02 per 10 woman years can be compared very
favourably with copper T users (0.25 per
woman years) and sexually active women not using any contraception (1.2-1.6 per
woman years). Nevertheless as LNG-IUS is so effective in preventing
intrauterine pregnancy, if a pregnancy does occur with the IUS still remaining
in womb then there is a high suspicion of being ectopic. The client should be
forewarned about this very rare possibility whenever period is missed and home
monitoring of UPT (Urine for pregnancy test) is positive.
2)
Perforation
of womb: Occasionally perforation
of womb can occur particularly when IUS is fitted in early postpartum period
when uterus is soft. Like copper IUD perforation can be confirmed by sonography
and will necessitate laparoscopic removal of the device under general anesthesia.
3) Risk caused
by systemic absorption of progesterone. The blood level while wearing LNG IUS
is 50% less than when women use minipill. Thus of all the hormonal
contraceptives adds minimum hormonal level in LNG-IUS blow this minimizes the
risk to her health. It is very unlikely that such minimal increase of
progesterone hormone in blood will exhibit any adverse effect on lipid profile
or cause arterial changes.
Timing of insertion of IUS:
1)
In regularly menstruating women IUS can be fitted
within first six days of commencement of menstrual period. No back up is
needed. If IUS is fitted seven days after commencement of period then barrier
contraceptive should be advocated for next seven days thus that allowing
sufficient time to exert its full contraceptive effect. However insertion may
be planned at any other day of cycle if there is no sexual intercourse in that
cycle.
2)
Six weeks after normal childbirth and four weeks after
induced or spontaneous abortion if there is no clinical evidence of sepsis.
Some people however have suggested fitting LNG-IUS as early as seven days after
an abortion procedure as soon abortion induced pain and bleeding pass off.
3)
Insertion during lactation ammenohea has been after
performed, with great satisfaction of acceptor. It can be done as early as 6
weeks but often carried out 8 weeks after normal childbirth. The use of sounding
however is contraindicated during such puerperal insertions because musculature
of womb is still soft and may cause perforation of womb. The acceptor may be
unnecessarily worried about health of child but the daily amount of LNG excreted
in 600ml of breast milk is approximately 0.1% of the intrauterine daily dose.
Thus there is interference in the development of the newborn.
Follow Up:
First follow up visit may be planned
one week after insertion and later on monthly basis for first three months. Other
after unless there is any complaint no routine follow up is recommended but she
should continue to feel the thread after each menstrual period and be satisfied
that the device has not silent fallen off the womb.
The idea of first follow up
arranging so soon is to discuss with the woman about bleeding symptoms and if
there be any pelvic pain. Additionally she should be encouraged to bear the inconvenient
of bleeding for couple of days. These simple encouraging words or even
telephonic advice will boost up the moral of client to continue the device in spite
of minor sick effects or discomfort.
At follow up visits she should be
enquired about any pelvic pain which may imply either descent of the device or
malrotation of the device while still remaining in womb to achieve near 95%
continuous rate the caregiver should offer ample opportunity to discuss her
concerns about IUS. The staff should be caring, helpful and never dismissive.
HCP should never cloud her doubts but should try to clarify the unspoken
concerns related to IUS. The duty of HCP is to check her blood pressure and
record weight HCP should then perform and interval exception and be satisfied
with the visible part of the length of thread though such interval exertion is
seldom required in intelligent women. However the continuation rate LNG-IUS is
85% after the end of one year and that of copper IUSs is 78%. At last she
should be reminded that LNG-US does not prevent STI and if she considers that
there is a possibility of STI. She should insist on barrier contraceptive in
addition.
Counseling tips:
LNG-IUS is usually very well
tolerated in women who have received careful counseling about the possibilities
of irregular bleeding for first two or
three month and subquently amenorrhoea.
But poorly counseled women may become concerned and even request removal of the
device. Thus before fitting IUS it is desirable that counselor should have an unbiased and unhurried discussion with
the acceptor and explain pros and cons of above all trust and confidence in the
care givers is as important as candid discussion on this costly contraceptive.
Not only the extensive counseling but successful use of LNG-IUS requires good
training of doctors who fit the IUS. In fact acceptance and continuation rate
of any contraceptive method are dependent on technical and counseling skills of
the providers. Further, management of side effects and due attention to
complaints also are important factors for high continuation rate poor selection
of users or poor counseling result in unnecessarily high request for removal of
device.
Copper being devices Vs. LNG-IUS:
Which device to choose? The opinion
of scientists varies in this regard. The side effects, failure rates,
discontinuation rates, spontaneous expulsion rates have been compared by
different health institutions. For average women cheaper T Cu 380 is better as
it has proven efficacy of long 12 years. But after though counseling if
potential acceptor is worried about persistent amenorrhoeic induced by Copper
being IUD the LNG-IUS may be a better option. No doubt women with gynecological
diseases like dysmenorrheal and endometriosis will opt for LNG-IUS. For
interested readers short comparison between the two commonly used devices is
mentioned below –
|
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Cu T
|
LNG-IUS
|
Cu T
|
LNG-IUS
|
Cu T
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LNG-IUS
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Cost
|
1-1.4 preg per 100 w years
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Do
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Failure rate
|
8.4 per 100 users
|
11.7
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Expulsion the rate
|
3.6 per 100 users
|
3.6 per 100 users
|
|
|
|
|
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PID incidence
|
|
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|
|
|
|
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Discontinuation rate
|
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Myths & Barriers to LNG-IUS use:
1)
There device promote pelvic infection (P.I.D.) thus
may invite infertility. In fact IUS do not promote P.I.D.
2)
The risk ectopic pregnancy is unacceptably high. The
reality is that incidence of ectopic pregnancy is considerably less end in LNG
users than general population not using contraception.
3)
The device may go to inside tummy. The rate of womb
perforation is very rare.
4)
The return of fertility is unduly delayed. This is not
true.
5)
It cannot be used in nulliparous women. In fact
nulliporous women can use it though introduction i.e. fitting of IUS may be
comparatives more difficult.
6)
Women affected with HIV cannot use IUS. IUS can be
used in women affected with HIV though it is considered as category 3 risk. But
IUS’ is very effective. So it can be used to achieve near 100% prevention of
pregnancy. Barrier contraception should be used concomitantly to prevent HIV
transmission.
The growing evidence suggests that barrier
contraceptive as commonly used do not prevent pregnancy all the time. That is
the reason why women suffering from STI should avail dual protection i.e. barrier (to prevent STI) along with some
effective contraceptives (to prevent conception).
Take home message:
The LNG-IUS was marketed in US in
the year 1995. It is a highly effective contraceptive method which can be
safely used for 5-year period. The release of levonorgestrel (LNG) hormone
(progesterone) inside the womb represents a new approach in contraceptive
technology as it (hormone) exerts local action thus avoids systemic side
effects related to hormone.
The levonorgestrel releasing
intrauterine system (LNG-IUS) continuously release progesterone hormone for at
least 5-7 years this offers an effective ‘estrogen
free long-acting, reversible contraceptive. It offers effective protection against ectopic pregnancy and due to its low systemic steroidal dose; any side effects are mild and few. It can be
fitted four to six weeks after childbirth. It does not affect production if breast
milk neither does it affect growth of infant.
There are some vices as well. The
device is costly and not distributed by Govt. of India nor subsidized by an NGO
in resource poor countries.
Many women do suffer from irregular vaginal bleeding for first few
months which may be annoying to them. But after four to six months most will
have regular periods and by one year majurity will achieve amenorrhoea i.e. nonoccurrence of
monthly periods. Inspite of all thee nuisances LNG-IUS does not predispose to any
health risk. Nevertheless LNG-IUS remains the only option for w9omen who intend
to have long term reversible contraception (no daily commitment). The other
such options are implanon and quarters shots. Subdermal implant ‘Implanon’
which is effective for three years are not readily available in most countries
including India. Hopefully this will be available in India by 2010.
LNG IUS (Mirena/Leno Nova):
These IUDs are almost same as copper
bearing IUDs except that the vertical limb of the T-shaped plastic frame is so
designed that it accomodets a small cylinder of progesterone hormone inside. This
progesterone filled cylinder
continues to release small amount of progesterone daily inside the womb for
five year continuously. The levonorgestrel releasing intrauterine system
(LNG-IUS) has now become one of the most effective contraceptive methods
available. Additionally this hormonal contraceptive primarily exerts its
contraceptive action by topical action on womb and there is minimal rise of
progesterone hormone in blood. Therefore, LNG-IUS has virtually no systemic
hormonal side effect. LNG-IUS thus is a hormonal
contraceptive method with the lowest hormonal does to be tolerated by a
woman. The common brand names are ‘Mirena’
IUS and Levo Nova the Mirena IUS is like many other types of Intrauterine
contraceptive Devices (sometimes located IUCD’s or coils) in that it is lay to
be fitted by a doctor and remains in the womb for a fixed amount of time, after
which it must be changed. It is different, however, in that it is much more
effective than usual IUD’s and avoids many of the side effects of copper
containing IUDs.
LNG-IUS exerts contraceptive effect at least for five years.
Nevertheless it continues to release small amount of progesterone in the fifth
and sixth year at a smaller dose i.e. at the rate of 14mcg/day. Even this small
dose is sufficient to effects contraception. After seven years, however, the
contraceptive efficacy falls markedly. Therefore many scientists now
recommended that LNG IUS is effective for seven years. In fact people have
tried for seven years and they are satisfied with its contraceptive efficacy in
last two years also.
or Progesterone Containg Intrauterine Contraceptive Device?
