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Intrauterine Insemination (IUI)

Intrauterine insemination, or as it is commonly called, IUI, is when the semen sample is "washed" or passed through a density gradient, separating sperm from semen; then concentrating the sperm and injecting it into the uterus by passing the vagina and cervix.

Putting semen in the uterus without "washing" it first can cause violent uterine contractions, the risk of anaphylactic shock and death; and, sperm can not fertilize as long as they are in semen. By washing semen and separating out the sperm, it is an extremely safe and effective means of putting sperm into the uterine cavity with a zero risk of complications.

Indications for Intrauterine Insemination (IUI)

Indications for Intrauterine Insemination (IUI) are:

  • Damage to the cervix from any cause that interferes with cervical mucus production
  • The absence of cervical mucus
  • Poor sperm-mucus interaction even with good mucus and a normal Semen Analysis (SA) (PCT)
  • Decreased sperm parameters - i.e. numbers, motility, morphology or semen volume
  • Unexplained infertility
  • Total Motile Normal Sperm (TMNS) count of at least 5 million or greater
  • More aggressive treatment than timed intercourse
  • Using donor sperm
  • Difficulty with "sex on demand" and/or getting an erection or ejaculation with intercourse

Natural vs. Stimulated Cycle

Intrauterine Insemination (IUI) can be done on a woman's natural cycle, where she makes one egg; or on a stimulated cycle, where she can make multiple eggs. The two medications used for stimulation or "super-ovulation" (SO) are:

  • Clomid - Taken orally between days 3-7 or 5-9 and makes about 1-3 eggs and has a multiple rate of 8% depending on age
  • HMG (Human Menopausal Gonadotrophin) - Injectable and given starting days 5 through ovulation and generally makes 2-5 eggs, with a multiple rate of 15-20% depending on age.

In both cases, 98-99+% of the time, the multiples are twins. Ultrasound will tell you how many egg follicles you are making and if there are more than 3-4, depending on age, the Intrauterine Insemination (IUI) is called off and the cycle is cancelled and started again next cycle on a lower dose of medication.

Clomid Success Rates vs. Human Menopausal Gonadotrophin (HMG) Success Rates

Just by simple math, Human Menopausal Gonadotrophin (HMG) works better than Clomid because it makes more eggs, and with more eggs the greater the chance that a sperm will find an egg and you will be successful. However, even if you make 2 eggs with Clomid and 2 eggs with HMG, the HMG has better success rates, because it "makes better eggs", "creates a better hormonal environment for pregnancy to occur", or "corrects something in 2009 that we can not measure"; but egg for egg, follicle for follicle, HMG has better success rates than Clomid. Therefore, the most successful way of doing IUI by super-ovulation (SO) - is with HMG; however, understanding that SO-IUI with Clomid can also be successful. Arizona Center for Fertility Studies believes that a woman should be given the pros and cons of all the options and when she is clear on the choices, choose one that is best for her.

Intrauterine Insemination (IUI) Procedure

At Arizona Center for Fertility Studies, Intrauterine Insemination (IUI) in done in the following manner.

Once the couple decides on going with a natural cycle versus a stimulated cycle, she calls on day 1-2 of her cycle and gets a screening vaginal ultrasound to rule out any ovarian cysts. If cysts are present, the IUI cycle is cancelled and she is offered birth control pills to get rid of the cysts. If no cysts are present, which is almost 100% of the time, than Clomid or HMG is started on the appropriate day of the cycle and ultrasounds are done every 2-3 days to monitor follicular (egg) numbers and development.

Once the follicles are mature, at least 18 mm in size, 10,000 IU of hCG is given to trigger ovulation. This will start the process of ovulation, or the release of the egg(s), predictively and very accurately, in about 38 hours. In human females, the process to actually release the egg takes about 4 hours. Therefore, 38 plus 4 equals 42, which is about the time the egg(s) will physically be released and picked up by the fallopian tube.

IUI, with the already washed sperm received 2-4+ hours earlier, is then placed into the uterine cavity using a small specialized catheter that is passed through the vagina and cervix. For the most part, there is minimum to no discomfort, however, a few women can experience mild cramping, and if they already know this, can take either Motrin, Alleve or Advil about a hour prior to the procedure.

The timing of IUI is critical, because there is a lot of evidence in the literature suggesting the sperm do not live in the uterus and only travel through it. Sperm, on the other hand, can live in the cervical mucus for an average of 3-4 days and from there travel up to the fallopian tube. It is estimated that sperm put in the uterus travels through it within 4-6 hours and afterwards it is all gone. If IUI is timed with anything other than the hCG trigger shot, there is a good probability that by the time ovulation occurs, and the egg is picked up by the fallopian tube, all the sperm are gone.

Examples of this would be:

  • If IUI was timed with the over the counter ovulation detection kits (ODK). Once the ODK turns positive, ovulation will occur in 26-40 hours. If IUI is done too soon or too late, by the time the fallopian tube picks up the egg(s), all the sperm may have already travelled out of the uterus and you will not be successful.
  • If IUI is timed with basal body temperature charts (BBT), by the time the temperature goes up indicating ovulation, the egg was released 36 hours earlier. Using BBT to time IUI is not much better than guessing when to do the insemination.
  • Timing IUI to when you think you should be ovulating, i.e. day 14 of a normal 28 day cycle or 16 of a normal 30 cycle, is also not much better than guessing, since sperm only stay in the uterus for approximately 4-6 hours, and you can not be sure ovulation is occurring when you think it is.

The best way to accurately time IUI is with a hCG trigger with insemination 42-43 hours later. Anything else, has a low probability of success and may explain why many IUIs are not successful. At Arizona Center for Fertility Studies, all cycles of natural-IUI or SO-IUI are done with hCG trigger; and yes, until we figure out how to have the ovary take the weekends off, work on the weekends, if that is when you need your IUI.

Intrauterine Insemination

Graphic representation of the mechanics of doing intrauterine insemination (IUI)

Intrauterine Insemination (IUI) Success Rates - Bell Curve

Doing IUI or Clomid/HMG alone is not as successful as doing the combination of SO-IUI. Clomid-IUI is twice as successful per cycle than a natural cycle-IUI at approximately 8% per cycle; and HMG-IUI is twice as successful as Clomid-IUI at about 12-15% per cycle.

Success is a bell shaped curve and takes an average of 3-4 attempts to be successful. By the end of 6 attempts at SO-IUI there is little to no success left. This is because you are doing the same thing over and over and are learning almost nothing about the cycle, so you can not change anything to improve success. Either on a natural cycle or with medication, you do not really know if the woman is making eggs or just cysts, whether or not the eggs are being released, whether the tube is picking up the egg(s), is sperm getting past the uterus, is fertilization occurring, is the embryo developing normally, did the embryo travel down the fallopian tube and into the uterus, and did implantation occur. All these things are learned with IVF but not with IUI.

Intrauterine Insemination (IUI) vs. In-Vitro Fertilization (IVF)

Interesting, 6 cycles of SO-IUI on injectable medication (HMG), takes at least 6 months, more if you have a cystic cycle, costs about the same, and is not as successful, as one cycle of In-Vitro Fertilization (IVF).

Then the question becomes, why does anyone do IUI?

The answer is that they gamble, hoping that IUI will work in 2-3 attempts, which is easier and costs less. However, after 4-5 unsuccessful attempts at IUI, you have spent the time, money and emotions; and generally then go on to do In-Vitro Fertilization (IVF).

Therefore, Arizona Center for Fertility Studies feels strongly that all the pros and cons of these two choices, Intrauterine Insemination (IUI) vs. In-Vitro Fertilization (IVF), be presented clearly and unbiasedly and once the couple fully understands their choices, than they should choose between being conservative or more aggressive. The choice should be theirs. If the choice is to be aggressive, they will know that conservative treatments could have been successful and they just did not choose that option.

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