Endometriosis is a disease where tissue resembling the endometrium, or the tissue that normally lines the uterus, starts growing outside the uterus forming lesions. These lesions swell and shed with the hormonal changes that control menstruation just like the normal endometrium, but because they are located outside the uterus, they cannot leave the body. This causes inflammation and results in pain and infertility.

What is intrauterine insemination?

Intrauterine insemination (IUI) is a method of assisted reproduction, which involves injecting sperm directly into a woman’s uterus.

IUI as an option for women with endometriosis

Following a diagnosis of endometriosis, patients wishing to conceive should meet with a fertility specialist to discuss the particulars of their case and determine the best method of assisted reproduction. The patient’s partner should also be tested to ensure sperm viability (motility, sperm count, etc). If the partner’s sperm is not viable, patients may opt to use donor sperm instead.

IUI is generally used for patients in the early stages of endometriosis.

How is IUI performed?

For IUI to be performed, patients will have to stop using any hormonal contraceptives. On the first day of their period, they will begin taking clomiphene citrate (a fertility medication) or artificial follicle stimulating hormone for five days to encourage ovulation.

There is a narrow window for ovulation (about 24 to 36 hours), and careful monitoring is required to ensure this window is not missed. Patients will go in for ultrasounds and blood tests to assess hormone levels from about the sixth day of the cycle until ovulation. If these tests indicate that an ovum is mature, the patient may be given an injection of a hormone called human chorionic gonadotropin (hCG) to stimulate the release of the ovum.

Immediately following this injection, either the patient’s partner provides a sperm sample or a donor sample from a sperm bank is injected into the patient’s uterus during a speculum exam using a thin tube.

The procedure feels similar to a PAP smear test. Most women report feeling only mild discomfort for one or two days following the procedure.

About 10 days after the procedure, patients can take an at-home pregnancy test. Positive results should be confirmed by a more accurate blood test. If a menstrual period starts, patients should discuss their options with their fertility specialist.

Generally, if patients have not conceived after about three rounds of IUI, their fertility specialist may recommend in vitro fertilization.

IUI research in endometriosis

In a study published in the journal Reproductive Biomedicine Online, researchers performed a retrospective analysis of two IUI treatment strategies carried out in patients with moderate to severe endometriosis. Patients received either IUI with ovarian stimulation (follicle stimulating hormone, hCG treatment, 20 patients, 61 reproductive cycles) or IUI without ovarian stimulation in the first three cycles followed by ovarian stimulation (45 patients, 184 reproductive cycles). Ovarian stimulation in combination with IUI resulted in eight pregnancies (40% success rate) compared with seven pregnancies (15.6% success rate) without ovarian stimulation.

An observational clinical trial (NCT03425604) examined patient records from a fertility clinic. A total of 9,979 patients and healthy volunteers who had received the IUI procedure were included in the study. The number of attempts and the number of pregnancies were compared between women older than 38 with and without endometriosis. The study was completed, but the results have not yet been published.

A clinical trial (NCT02636400) is ongoing in Belgium to assess the role of IUI in endometriosis patients. A total of 24 patients with endometriosis who recently had a complete laparoscopic endometriosis resection will be randomly assigned to receive either controlled ovarian stimulation with hCG and four cycles of IUI within seven expectant cycles or no treatment for seven cycles (the control group). The primary outcome to be measured is pregnancy rate.

A Phase 3 clinical trial (NCT02470169) is currently recruiting 450 endometriosis patients in Egypt to assess the success rate of stimulated versus unstimulated IUI cycles. Patients will be randomly assigned to receive hCG and IUI, IUI alone, or no artificial insemination. The primary outcome measure will be pregnancy rate.


Endometriosis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.