Intrauterine device
The Intrauterine Device (IUD) is the most widely used
reversible form of contraception in the world (Nelson et al.,
2006).
Historical overview:
A frequently told, but not well-documented story, assigns the
first use of IUD to caravan drivers who allegedly used intrauterine stones to prevent
pregnancies in their camels during long journeys (Speroff
and Darney, 2005).
The first IUDs for women were developed in nineteenth century
in Germany as
variation of vaginal pessaries. These early IUDs were rigid metal appliances,
small button-like structure that covered the opening of the cervix and that
were attached to stems extending into the cervical canal (Huber et al., 1975). They were multipurpose devices that only
indirectly acted as contraceptives (Tatum et al., 1996).
In 1902, a pessary that extends into the uterus was developed
by Hollweg in Germany
and used for contraception. This pessary was sold for self- insertion, but the
hazard of infection was great, earning the condemnation of the medical
community. In 1909, Richter succeeded to introduce a silkworm catgut ring with
a nickel and bronze wire protruding through cervical os (Richter,
1909).
Although there is no written record of haw the male partner responded
to this metal protrusion at the top of vaginal vault, in 1923 Pust combined
Richter's ring with the old button-type pessary and replace the wire
with catgut threads (Pust, 1923).
Given that these devices were used by women during the world
ware before antibiotics or non steroidal anti-inflammatory drugs, their use quickly
became associated with serious infections and significant patient discomfort.
These side effects created such an enduring negative image for IUDs that when Grafenberg
introduced the first IUD in the 1920s; it was generally rejected by the
medical community.
The Grafenberg ring was tailless device composed of
German silver an alloy of copper, nickel, and zinc. Because of its extreme
flexibility, expulsion could easily remain undetected, exposing the user to
unwanted pregnancy (Speroff, and Darney, 2005).
Ota in Japan solve the problem; he added a small central disk
with three spokes that radiated out to the inner surface of the gold or gold- plated
ring to stabilize the device and reduce expulsion rate and he called it Ota
ring (Ota, 1934).
Throughout World War II and in the first two decades after
World War II an awareness of explosion in population and its impact began to grow.
In 1959, reports from Japan
and Israel by Ishihama
and Oppenheimer, respectively, once again stirred interest in the rings.
The Oppenheimer report was in the American Journal of Obstetrics and Gynecology,
and several American gynecologists were stimulated to use rings of silver or
silk and triggered an outpouring of creative new devices by others (Ishihama, 1959 and Oppenheimer, 1959).
In the 1960s and 1970s, the IUD thrived. Techniques were
modified and a plethora of types were introduced. The various devices developed
in the 1960s were made of plastic (polyethylene) impregnated with barium
sulfate so that they would be visible on an x-ray (Speroff and
Darney, 2005).
The Margulies coil, developed by Lazer Margulies (1960) at Mt.
Sinai Hospital
in New York City was the first
plastic device with a memory, which allowed the use of an inserter and
reconfiguration of the shape when it was expelled into the uterus. The coil was
a large device (sure to cause cramping and bleeding), and its hard plastic tail
proved risky to the male partner (Speroff, and Darney,
2005).
In 1962, the first international conference on IUDs in New
York City at the suggestion of Alan Guttmacher.
In the conference, Jack Lippes of Buffalo
presented his experience with his device (Lippes Loop), which fortunately,
had single filament thread as a tail. The Margulies coil was rapidly replaced
by Lippes Loop, which quickly became the most widely prescribed IUD in united
state in 1970s. (Speroff, and Darney, 2005). Many
other devices came along, but, with the exception of the four sizes of Lippes
Loops and the two Safe-T-Coils, they had limited use. Stainless steel devices
incorporating springs were designed to compress for easy insertion, but the
movement of these devices allowed them to embed in the uterus, making them too
difficult to remove. Majzlin Spring is a memorable example (Speroff,
and Darney, 2005).
In 1970, the investigators at Johan Hopkins developed the Dalkon-Shield
an all plastic device with small plastic protrusions around its edges to help
it adhere to the endometrium and reduce the risk of expulsion. Within 3 years,
a high incidence of pelvic infection was recognized. The multifilament tail
enclosed plastic sheath of the Dalkon Shield provided a pathway
for bacteria to ascend protected from the barrier of cervical mucus (Tatum et al., 1975).
Burkman (1981) reported
that the greatest risk factor for PID with IUD use was multiple sex partners.
When women with one partner who had never used IUD were used as the referent
population, women who had one partner who used a copper IUD showed no increased
risk for primary tubal infertility. In contrast, women with multiple sexual
partners who used IUDs showed an increased risk for tubal infertility (Cramer et al., 1985 and Daling et al., 1985). Studies
conducted in developing countries have found that the incidence of PID is only
about 1 case per 1000 insertions (Skjeldestad et al., 1996 and
Walash et al., 1998). The addition of copper to the IUD was
suggested by Jaime Zipper of Chile
in 1969, whose experiments with metals indicate that copper acted locally on the
endometrium (Zipper et al., 1969). Howard
Tatum combined Zipper's suggestion with the development of the
T-shape to diminish the uterine reaction to the structural frame and produced
the copper-T. The first copper IUD had copper wire wound around the straight
shaft of the T, the TCu-200c it had 200mm2 of exposed copper wire, also known
as Tatum-T. (Tatum, 1983). Tatum's
reasoning was that the T-shape would conform to the shape of the uterus in
contrast to the other IUDs that required the uterus to conform to their shapes.
Furthermore, the copper IUDs could be much smaller than those of simple inert
plastic devices and still provide effective contraception.
The Cu-7 with a copper wound stem was developed in 1971 and
quickly became the most popular device in the U.S.
Both the Cu-7 and the Tatum-T were withdrawn from the United
States market in 1986 by G.D.Searle and
company (Speroff and Darney, 2005).
IUD development continued, however. More copper was added by
Population Council investigator, leading to the TCu380A which have 380mm2 of
exposed copper surface area with copper wound around the stem plus a copper
sleeve on each horizontal arm (Sivin et al., 1991). The
"A" in TCu-380A is for arms, indicating the importance of the copper
sleeves. Making the copper solid and tubular increased effectiveness and
lifespan of the IUD. The TCu-380A has been in use in more than 30 countries
since 1982, and in 1988, it was marketed in the United
States as "ParaGard".
0 التعليقات
إرسال تعليق