Silverlily and Goldlily IUDs: - The European Society of Contraception ...

Silverlily and Goldlily IUDs:
do alloys create a new generation of
intrauterine contraceptive devices?
Istv István án Batár
Family Planning Center, Department of Obstetrics and
Gynecology, University of Debrecen, Hungary
9th Congress of the European Society
of Contraception
Istanbul, Turkey, May 3-6, 2006
April 2006 IB * UDMHSC 1
Corrosion of copper
• Eroded surface
“splinting” effect:
- scale-like formation
- sharp-edged structures
• Microscopic damage of
the endomertium
spotting/bleeding, endometritis
• Copper loss
decreased efficacy
• Broken wire
shortened lifespan
April 2006 IB * UDMHSC 3
Overcoming the problem of corrosion 2
4. Using alloys
combining Cu with Ag/Au
• electrochemistry:
corrosion of alloy is smaller
than that of pure copper
• surface corrosion:
thin, greenish, velvety layer
• noble metals: mortar effect
Ag/Au keeps the integrity
of wire after Cu dissolution
(no fragmentation)
April 2006 IB * UDMHSC 5
1.
Intrauterine devices are still a
“modern” method of contraception
Directions of current innovations
• Hormone-containing intrauterine systems
(Mirena, FibroPlant)
• Frameless (flexible) intrauterine implants
(Different GyneFix designs)
• Using alloy metals instead of pure copper
(Solving the problem of copper corrosion)
April 2006 IB * UDMHSC 2
Overcoming the problem of corrosion 1
3.
2.
1. Increasing the diameter of
copper wire
Multiload devices (MLCu250/MLCu375)
(longer time needed for breaking)
2. Using Cu cylinder
TCu 380
(thicker wall of copper cylinder)
3. Using a silver core in the
copper
Nova T
- no wire breaking
- longer lifespan
But, neither of them can solve
the oxidation of the wire
surface! (splinting >>> spotting)
April 2006 IB * UDMHSC 4
Advantages of copper/noble metal alloys
Uterine fluid
(electrolyte)
• No rough surface destruction
less spotting/bleeding
• Higher Cu dissolution
(250 mm 2 alloy = 380 mm 2 Cu)
higher, stronger Cu effect
• Electrostatic/chemical effect
local tiny galvanic (alkaline)
batteries
- decreased sperm motility
- impaired sperm capacitation
- shortened sperm survival time
• Oligo-dynamic effect
- bactericide
- fungicide
April 2006 IB * UDMHSC 6
1

Silverlily and Goldlily IUDs
April 2006 IB * UDMHSC 7
Silverlily and Goldlily IUDs
Clinical study characteristics 2.
Patient characteristics
Average age (years)
Average # of birth (n)
Average # of living children (n)
Average # of ind. abortion (n)
Average # of spont. abortion (n)
Average # of ectopic pregn. (n)
Silverlily
31.49
2.05
2.02
0.94
0.25
0.02
0.23
0.01
April 2006 IB * UDMHSC 9
Silverlily and Goldlily IUDs
Terminations
Pregnancy
Expulsion
Removal for
bleeding/pain
other medical reasons
Competing risks, total
Silverlily
1-12
months
LT rates
0.7
1.9
6.1
2.2
13.7 *
1-120
months
Goldlily
32.42
1,96
1.95
0.84
April 2006 IB * UDMHSC 11
P.I.
1,09
1,33
4,79
2,41
14,46
Goldlily
1-12
months
LT rates
0.7
2.0
5.3
2.2
11.8 *
1-120
months
1,23
1,52
4,24
2,06
12,60
LT rates calculated for 100 users P.I. = calculated for 100 users/one year
* Chi-Square = 4.2673; Probability < 0.05
P.I.
Silverlily and Goldlily IUDs
Clinical study characteristics 1.
Type of study
• Human phase IV
(post marketing)
• Prospective
• Non randomized
• Open label
Statistical method
• Life table
- gross cumulative
- first year of use
• Pearl-index
cumulative use (10 years)
• c 2 calculation
April 2006 IB * UDMHSC 8
Silverlily and Goldlily IUDs
Clinical study characteristics 3.
Characteristics
Insertions (n)
At risk (n), 1 st year
10 th year
CWMU (month)*, 1 st year
10 th year
Silverlily
3,290
1,954
63
27,762
102.725
* CWMU = Cumulative Woman-month of Use
Silverlily 1990-2005, Goldlily 1993-2005
Goldlily
4,055
2,253
63
32,628
114.840
April 2006 IB * UDMHSC 10
Silverlily and Goldlily IUDs
Conclusions
• Both devices provide good protection
against unwanted pregnancy
• Relevant termination rates are low
• Continuation rates are high
(first year figures: Silverlily 86.3%, Goldlily 88.2% )
• Using alloy of Cu/Ag and Cu/Au provides a
new possibility in intrauterine contraception
(longer life span, less side effects )
• Copper/noble metal alloys may create a new
generation of IUDs
April 2006 IB * UDMHSC 12
2