History of the IUD
Introduction by Alfred N. Poindexter, III, MD:
Welcome to a discussion of modern IUD use. I have, on my right, Dr. Paula Hillard, Professor of OB/GYN and Pediatrics at the University of Cincinnati; and on my left, Dr. Catherine Lynch, Associate Professor of OB/GYN at the University of South Florida. And I am Dr. Alfred Poindexter, Professor of OB/GYN at Baylor College of Medicine.
What we will do today is to discuss with you the history of IUD use, follow that with mechanisms of action, and then practical applications of IUD use, and then have some discussion of these issues. We'll first start with Dr. Lynch presenting the history of IUD use.
Thank you. Today I'd like to talk to you about the intrauterine device, or IUD. I'm first going to give a little background on the utilization of the IUD, then cover the history of the IUD, then look at the mechanisms of actions, the products that are currently available today; and then finally we'll take a look at side effects and costs of the IUD.
As we can see here, approximately 90% of women are at risk for unintended pregnancy, but less than 1% in the United States actually utilize the intrauterine device as a method of contraception.
Use of the IUD
A lot of that has to do with somewhat of a controversial history related to the IUD; and we can take a look at this graph that demonstrates the change in utilization of the IUD in the United States versus the rest of the world when the problems with the Dalkon Shield became very prominent in the United States, and as we take a look at the significant drop-off and poor utilization of the IUD between 1982 and 1988 in the US, while the rest of the world's market was increasingly using the IUD as an effective method of contraception.
History of IUD's
To understand the history of the IUD, we are going to go back and actually look at the history to the very early IUDs. And it's been often cited, but not very well documented, the idea that perhaps some of the camel drivers would place stones within the vaginas of their camels as a contraceptive method to avoid the camels' getting pregnant on long trips. More well-documented IUD use actually is first reported in the early 1800s with the idea of stem pessaries which were designed to cover the opening of the cervix and may actually have gone within the cervix slightly. In 1902 Hallwig designed a stem type pessary that actually extended the stem into the uterus itself. Interestingly enough, it was sold for self-insertion; and, however, there was a very high infection rate associated with this, and so it was condemned by the medical community. However, in 1909, Richter devised a product that used a silkworm catgut ring with both nickel and bronze wire. And then shortly thereafter, Pust in 1923 combined the ring with a button. This was highly utilized during World War I. However, since the button had a catgut thread associated with it, it, too, was associated with a high incidence of infection. In 1930, Graefenburg made some improvements; and he removed the tail and the pessary as he thought that those were sources of the infection, and in fact had a very good product and good result. However, in Germany at the time, contraception was not only not encouraged but strongly discouraged; and so he was jailed and ultimately exiled. The contraceptive device did have a high expulsion rate. Oda in 1934 in Japan also modified this contraceptive device slightly, adding a supportive structure to the ring. But also in Japan, contraception wasn't encouraged; and he, too, was exiled.
History of IUDs: 1960s
In the early 1960s, after World War II with the baby boom population, IUDs really began to thrive with such devices as the Marguiles coil, that was the first plastic device that actually had an inserter available and a reconfigurable structure to facilitate the placement of the device. The coil, however, was very large, which caused a great deal of cramping and bleeding; and there was a hard plastic tail that frequently resulted in discomfort for the male. In 1962 there was the first conference on the actual IUD, which began the idea of comparing different products and looking at efficacy rates overall. And at this time Jack Lippe presented his product, the Lippes Loop, which had a single filament thread and became the most widely prescribed IUD in the 1970s. Tatum in 1968 described the Tatum T, and Zipper then added copper to the Tatum T, as he found that the copper provided additional contraceptive benefit.
That brings us to the Dalkon Shield, which was introduced in 1970 by Lerner. By 1973 Tatum actually began to report the idea that there was a design flaw because of the multifilament tail. The design of the Dalkon Shield itself was created in order to decrease the expulsion rate. Although sales were discontinued in 1975, the actual call for removal of the IUD wasn't until the early '80s, which allowed for further problems with infection to continue. There are multiple publicized reports of infections, septic abortions, and infertility following the utilization of the IUD, and by 1986 in the United States only the Progestasert was available on the market.
IUDs: Mechanisms of Action
So now let's move to the mechanism of action of today's IUD. There are many people who are afraid to use the IUD for they fear that it's actually an abortifacient. But there are many well-documented reports of the actual mechanism of action of the IUD that show that it actually interferes more with sperm migration and sperm function. It also impairs fertilization and inhibits implantation. Copper in very high concentrations in the cervical mucus can impede the actual sperm migration. It's been documented that fewer sperm are present in fallopian tubes of IUD users, and those that are actually recovered from within the fallopian tube are damaged and incapable of fertilization. Alvarez in 1988 also did a study in which women who were undergoing tubal ligation, who were not utilizing any other method of contraception, had their tubes flushed and the uterine cavity flushed for evaluation of the presence of sperm and fertilized ova, and found that those women who used the IUD actually had very few sperm in the fallopian tubes, and there were no fertilized ova - or fertilized eggs - at all. However, those who were not using any other method of contraception had several fertilized ova found. So again, the mechanism of action seems to be more on the impairing fertility and impairing sperm function versus actually impairing implantation.
IUDs: An Abortifacient?
So we can see here that the IUD as an abortifacient is actually a myth, and it's not really one of its mechanisms of action at all. Embryonic losses have also been taken a look at, using very sensitive HCG markers. Wilcox took a look at this and found that there was no elevation, or no measurable HCG in IUD users as compared to non-users, in which sensitive HCGs were positive many more times in the non-IUD users. Again, both Ortiz and Segal took a look at HCG levels in the luteal phase in IUD users, and again found that there was no significant elevation in the HCG.
The theory behind this is, again, can be correlated to that of a contaminant in the IVF lab for those patients who undergo in vitro fertilization. If there is any sort of contaminant in the lab, it totally impairs the likelihood of actual fertilization taking place.
Types of IUDs
Now let's take a look at the types of IUD. We have the copper-T 380A, known as the copper-T or the ParaGard; the progesterone-releasing IUD, known as the Progestasert; and the levonorgestrel-releasing IUD, known as the Mirena. The Progestasert will be discussed today merely as a now historical point, as it's no longer available on the market.
Copper T IUD
The copper-T IUD contains a polyethylene product with barium sulfate to allow it to be radiopaque, and a total of 380 millimeters of copper. The copper is dispersed between 318 square millimeters in the stem and 66 millimeters in the arms. The lifespan overall for the copper-T is ten years, and the cumulative total pregnancy rate by seven years is 1.6 per 100 women. There is an overall tenfold reduction in relative risk of ectopic in women using the copper-T.
The progesterone-releasing IUD contains also a co-polymer. There is a reservoir of 38 milligrams of progesterone, and it also has the barium sulfate to make it radiopaque. It releases 65 micrograms per day of progesterone into the cavity and has a lifespan of one year. The annual pregnancy rate is 3 per 100, and the relative risk of ectopic is actually slowly increased at 1.5 to 2.8, although the overall risk is very low because the pregnancy rate itself is very low. And as mentioned, it's no longer available.
The latest introduction into the market is that of the levonorgestrel IUD known as the Mirena. And it contains polyethylene with a central cylinder containing the levonorgestrel, releasing 20 micrograms per day of levonorgestrel, with a lifespan of five years. In some studies it may actually have a longer lifespan and has a very effective failure rate of between .1 and 1.1 per 100 women years. And there is no increased risk of ectopic.
Absolute and Relative Contraindications
What are our absolute and relative contraindications for the use of the IUD? Well, needless to say, an absolute contraindication is confirmed or suspected pregnancy. A pelvic malignancy is also an absolute contraindication. Undiagnosed vaginal bleeding needs to be investigated prior to utilizing the IUD. Known or suspected PID. Reported behaviors placing the patient at increased risk of PID. And also Wilson's disease for those that might use a copper device.
Relative contraindications include problems with the uterine size or shape, making it difficult for the IUD to be placed. Medical conditions that may increase the risk of infection. Nulligravidity, and we'll get into a discussion on that in a little while. Abnormal Pap smears. And a history of ectopic. Again, those are relative contraindications.
IUD Side Effects
The IUD side effects include that the most common reason for removal in 5 to 15% of patients is that of bleeding and cramping, and this is predominantly associated with the copper IUD. The progesterone-releasing and levonorgestrel-releasing IUDs actually have a decreased incidence of bleeding problems. Infection at the time of the placement of the IUD is felt to be the predominant trigger of infection in those who get infection with an IUD in place, due to contamination of the endometrial cavity. It is not associated with an increased risk of infertility if placed in a properly screened individual and inserted in a proper fashion. And also expulsion is a potential side effect.
IUDs and STDs
Now in terms of IUDs and STDs, we first need to realize that the IUD certainly doesn't provide any protection against STDs. So, just like with any other non-barrier method of contraception, a condom should be encouraged for anyone who is in a new relationship or is at any sort of risk for STD. There is an increased risk of PID at the time of insertion, and that's generally due to the presence of bacterial contaminant at the time of insertion. The highest risk seems to be within 20 days post-insertion. In the presence of salpingitis, tuboovarian abscesses, or severe pelvic infection, the IUD should be removed.
Now let's take a look at the cost effectiveness of the IUD. The copper-T IUD can be utilized for up to ten years. The package cost to the physician is $275. The cost to the patient is $320 with an insertion cost of approximately $270, giving an overall patient cost of $590. However, when you look at that as a per year cost, it's merely $59 a year. Similarly the Mirena, which is, as I said, good for five years, costs $355.50. The patient cost is $497, again with a $270 insertion fee, yielding a $767 total cost to the patient, making a per year cost of $153.40 per year. So if you were to compare that to your monthly co-pay for oral contraceptives, both of these methods are highly effective as well as relatively inexpensive contraceptive means for many patients.
So in summary, IUDs are a highly effective method of contraception. The IUDs on the market today are very safe when patients are appropriately screened. IUDs do not act as abortifacients, and IUDs are very cost effective if used for the intended duration.
Now I'd like to introduce Dr. Paula Hillard, who is going to talk to us about ACOG guidelines, insertion techniques, and the use of IUDs in special populations. Paula?