Unstimulated intrauterine insemination is an infertility treatment that is quite close to using natural methods to get pregnant. It involves using the male partner’s sperm to artificially inseminate the female partner by placing the sperm directly in her uterus during the time of the month when she is most likely to have just ovulated. This is more likely to be successful than natural sex, which introduces sperm into the vagina and cervix.
Unlike stimulated intrauterine insemination, IUI does not involve the use of hormonal treatments or fertility drugs to boost egg production or to prepare the uterus.
If you have been trying to get pregnant for between one and two years, couples in countries that offer infertility treatments are usually welcome to have an assessment to find out what the problem is. Unstimulated intrauterine insemination is often recommended if:
Both partners need to be assessed before intrauterine insemination can be planned. Sperm samples from the male partner need to be checked to make sure that the sperm count is good, and that plenty of the sperm are active and swim well. If this is not the case, you may need in vitro fertilisation.
The female partner will need an examination of her fallopian tubes and uterus to make sure that at least one tube is open, and that there are no abnormalities or adhesions in the uterus that could prevent natural conception. This involves having a laparoscopy under general anaesthetic. A thin tube with a camera built in is inserted into the abdomen to give the doctors a good view of the ovaries and uterus. A dye test is then used to make sure that dye can move easily through the fallopian tubes.
If one fallopian tube is blocked, but the other is fine, it is still possible to have unstimulated intrauterine insemination, but you will need ultrasound scans to show that you are producing a mature egg from the ovary on the clear side, before insemination takes place.
If all the tests have been completed without problems, your monitoring will begin around 12 days after the start of your last period. Blood or urine tests or a home ovulation predictor kit will then start to monitor your blood hormone levels to predict when you are about to ovulate. Just before an ovary releases an egg into the top of the fallopian tube, there is a surge of hormones that is easily detectable.
You will need to go into your infertility clinic 36–40 hours after this to have your intrauterine insemination. This is very quick and usually takes not much longer than a cervical smear test. The sperm from your partner, collected 3 hours before and washed and spun to choose the healthiest swimmers, are introduced directly into your uterus using a thin tube that is placed through your cervix.
After a short rest, you can then go home; there is no evidence that lying still will give you a better chance of getting pregnant.
The same technique is used to introduce the sperm but instead of these being collected fresh from the woman’s partner, a vial of frozen sperm collected from the sperm bank is thawed and prepared and then inserted into her uterus.
The statistics on success rates for unstimulated intrauterine insemination are not available separately from IUI cycles in which stimulation is used, but the overall success rates are quite low compared to in vitro fertilisation. Fewer than 16 % of women under 35 having intrauterine insemination become pregnant, and this proportion falls to 11 % for women who are slightly older (35–39).
It is quite likely, therefore, that you will not be successful first time. Most infertility specialists would attempt unstimulated intrauterine insemination maybe three times, before recommending using stimulated IUI and/or trying in vitro fertilisation.