Intrauterine Insemination


When a couple has intercourse, the average man will ejaculate around 100-200 million spermatozoa. Some of these spermatozoa don’t move or are too slow and some are not normal (morphologically abnormal in medical terms). Also spermatozoa are very sensitive to the vaginal acid environment. The cervical mucus (the mucous secretion produced from the woman’s uterus) is very thick and works as a natural filter for these spermatozoa. Many good spermatozoa will die due to the vaginal acid or be caught in this mucus as well. It is thought that around 99% of these sperm will not make it through. This means that out of the 100-200 million your partner ejaculated (on average), only a few hundred thousand with get in and start their journey across the uterus and the fallopian tube. This journey is not easy either. Spermatozoa are so small that you can put 200 of them in a line (head to tail!) into 1 mm. and they now need to swim 6 cm of uterus and then 15 cm of fallopian tube.

Intrauterine Insemination (IUI)

In patients in which we believe have good prognosis, maybe the spermatozoa are not in their best numbers or are just a little lazy, where everything else is working well, that haven’t been trying for too long, and maybe just increasing the number of spermatozoa that reach the egg could be a good idea.

Intrauterine insemination (IUI) is a clinic based fertility treatment that combines ovulation induction with introduction of prepared semen into the uterine cavity to facilitate fertilisation. The goal is to increase the number of sperm that reach the fallopian tubes and subsequently increase the chances of fertilisation and pregnancy.


  • Mild male factor infertility
  • Some cases of unexplained infertility
  • A hostile cervical condition, including cervical mucous problems.
  • Ejaculatory and erectile dysfunctions
  • Using Donor sperms including single women and same sex couples

Steps in a typical IUI cycle

The course of your treatment would be decided by your Fertility consultant based on the results of your fertility testing and of course your personal preferences.

  • You will attend the clinic for a nurse consultation which involves consent signing, viral screening and injection teach.
  • Female partner starts FSH injections on the first few days of her cycle and continues until she is ready for trigger injection (the injection that will make you ovulate).
  • Our nurses will have to perform some scans just to make sure you are not responding excessively to the medication and too many follicles (with their egg inside) are growing. Remember the more follicles growing the higher the chances of have multiple pregnancies (twins, triples, cuadruplets!). Multiple pregnancies are high risk pregnancies and the last thing we would like to do is put your babies at risk!
  • Trigger injection is administered once the leading follicle is over 18mm.
  • Couple attends the clinic in the next 12-36 hours for their IUI where the partner produces a semen sample (or the donor sperm is thawed) which is prepared and purified in lab (so it only contains motile sperm), and this prepared semen is then introduced directly into the woman’s uterus with a fine soft catheter. This procedure is quick and painless.
  • Female partner will have to start using progesterone support either in the form of vaginal gel, rectal suppositories or injections after the procedure.
  • Pregnancy test is carried out two weeks later of the insemination.

 Potential risks with IUI

IUI is generally a very safe and easy procedure. It is very well tolerated with a few patients complaining of cramping afterwards. The main potential risk is multiple pregnancy (getting pregnant with more than one baby) and it is calculated to happen in about 10% of patients.

IUI using Donor sperm

IUI can be performed with donor sperm in single women, same sex couples, and sometimes in couples where there is significant male factor involvement.

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