Intrauterine insemination (IUI) is a procedure in which sperm are placed directly into the uterine cavity through a catheter near the time of ovulation. This procedure is most commonly performed when there are problems with the sperm, such as low count or low motility, or an incompatibility between the sperm and the cervical mucus. It can also be performed to overcome problems associated with a man’s inability to ejaculate inside the woman’s vagina due to impotence, premature ejaculation or other medical conditions. IUI increases the chances of pregnancy because the sperm are placed directly in the uterus, bypassing the cervix and improving the delivery of the sperm to the egg.
Usually the woman’s ovaries are also simultaneously stimulated to produce two to four oocytes. These manipulations have certain advantages over the natural situation. Firstly, many more sperm are spared from destruction in the vagina and they are directly placed in the uterine cavity. Secondly, the distance which sperm have to travel to reach the site of fertilization in the fallopian tube is greatly shortened. Thirdly, more oocytes are available in the fallopian tubes and this increases the chances of a at least one of them being fertilized. Finally, the presence of more than one embryo likewise improves the chances of one of them implanting successfully in the uterus. IUI is one of the simpler and less expensive assisted conception treatment methods. Its effectiveness is such that it is now regarded as a suitable first line assisted conception treatment for most infertile couples with patent fallopian tubes.
IUI
Timing
IUI is timed to occur as close to ovulation as possible. Since the actual moment of ovulation is rarely known or witnessed, knowledge of the time-course relationship between the LH surge or administration of hCG and ovulation is important.
Not all follicles ovulate the same time; rather they do so in waves. These considerations have led some clinicians to carry out insemination twice, separated by 24 hours, around the time of ovulation. The first insemination is carried out 24 hours after administering HCG is administered and the first insemination carried out immediately following detection of the surge. The immediate insemination is due to the uncertainly of the exact interval between the onset of the LH surge and its detection. In such instances the second insemination may be optionally carried out 24 hours after the first one.
The more accurate the monitoring methods used, the fewer the number of required inseminations since the time of ovulation will be known with greater certainty.
Procedure The volume of the prepared sperm sample should be restricted to 0.5ml.
The woman lies in the lithotomy position (which approximates to lying on her back with the knees and hips flexed and thighs spread apart). A warm speculum is moistened with warm sterile water and gently inserted in the vagina to expose the cervix and cervical os. The cervix is gently wiped with several cotton wool balls soaked in normal saline solution. The insemination cannula is attached to the 1 ml syringe and used in drawing up the sperm suspension. The cannula is then gently introduced into the uterine cavity through the cervical canal and the sperm suspension gently expelled. All instruments are withdrawn and the patient allowed to lie on the procedure cough for some minutes before going home. A pregnancy test is carried out about two weeks later.
Success Rates
About 10-15% of couples will become pregnant in each cycle of treatment. Higher pregnancy rates of up to 34.3% have been reported by some workers. Most couples who get pregnant using IUI do so within the first four cycles of treatment. These four cycles can often be competed within a period of 8-12 months. It is not advisable to continue treatment with IUI after number o attempts. Instead, the patient should have IVF treatment if she still not pregnant.
Complications
Complications are not common following treatment with IUI.
The incidence of multiple pregnancy is increased (11 - 30% of pregnancies) because the ovaries are stimulated to produce more than one oocytes and there is no control over the number of resulting embryos that implant. The ovaries may become overstimulated in about 1% of cases leading to ill health, which may last for two weeks or more. This is called ovarian hyperstimulation syndrome.
The incidence of miscarriage is between 20 and 30% and the ectopic pregnancy rate is 3-5.5%; these rates are similar to those obtained following IVF and other assisted conception treatments.
Conclusion IUI now has an established role as a low risk, low cost, front line, assisted conception treatment method. Its efficacy is enhanced when patients are carefully screened to avoid treating those with contraindications such as suspected tubal disease.
Data has shown that making four attempts at IUI before resorting to IVF treatment is a reasonable strategy. Cost-effectiveness studies support this approach at managing infertile couples.