What Are the Success Rates of Intrauterine Insemination (IUI)?

By BSc, MSc (embryologist), MD, PhD, MSc (gynecologist), BSc, MSc (embryologist) and BA, MA (fertility counselor).
Last Update: 01/09/2019

To achieve a pregnancy by means of Intrauterine Insemination (IUI), meeting the minimum requirements is required. Otherwise, the treatment cycle would fail and reproductive success will occur.

In many cases, the first treatment cycle fails, but success is achieved in the second, third, or fourth. This is because IUI has a cumulative success rate. Continue reading to get more info.

Provided bellow is an index with the 8 points we are going to expand on in this article.

When does IUI actually work?

As explained above, as long as one meets the minimum requirements to be referred to this technique, it can be the solution to infertility. A large number of couples with mild-to-moderate fertility issues are able to become parents through this fertility treatment.

The following are the basic requirements:

  • Good sperm motility
  • Natural ovulation, either induced spontaneously or with medications
  • Tubal patency

In any case, even in those patients who meet these three criteria, achieving success with IUI might depend on other factors such as the cause and duration of infertility, the hormone treatment applied, the age of the woman, or the qualities of the endometrial lining (uterine layer where the embryo attaches).

Here is how some of these additional factors can affect IUI success rates:

Woman's age

A woman's reproductive potential decreases over time until its complete vanishment during a period we all know as menopause. As get closer to this phase, the egg count and quality decrease. This is the reason why, from ages 35-37, the chances of getting pregnant by IUI are rather low.

In these cases, other techniques to achieve pregnancy artificially, such as conventional IVF or IVF with ICSI are more likely to lead to pregnancy.

Ovarian stimulation cycle

Individualizing each case and protocol of medications to stimulate ovarian function and ovulation is crucial to succeed.

An excessive dose of stimulation drugs can cause the maturation of too many follicles (ovarian structures where eggs grow). This can be counterproductive, since it can diminish egg quality and increase the multiple pregnancy rate to a large extent.

A multiple pregnancy carries more risks than a singleton pregnancy for both the mother and the baby.

Endometrial thickness

The endometrium (lining of the uterus) is the place of the female reproductive tract where embryo implantation occurs, giving rise to a new pregnancy. For this to be possible, it must be receptive, that is, be in optimal conditions to receive the embryo.

It is crucial that your endometrium has a triple line pattern (three parallel layers are seen on the ultrasound scan) and a thickness of 8-10 mm. Should your endometrium not be on optimal conditions for embryo implantation, it might not take place. In other words, the treatment will not be successful.

Cause of infertility

Insemination translates into some small assistance in the natural process of conception, since the only thing we do is placing the sperm in the maternal uterus. This means that they have to reach the egg by themselves, as in natural fertilization.

Thus, if there are severe infertility issues in both the woman and the man, it is unlikely that natural fertilization occurs, and IUI would be useless.

Problems like severe endometriosis (stage IV), asthenozoospermia, oligospermia, azoospermia, chromosomal abnormalities, etc., are some examples of infertility problems that can lead an IUI cycle to fail.

Did you know that we can help you to choose a fertility clinic for your IUI cycle? All you have to do is get your Fertility Report now. It is an easy-to-use tool that is capable of filtering the best clinics and tailor an individual report exclusively for you with useful tips that will help you make a well informed decision.

Different types of success rates

When we talk about success rates, we should take into consideration the fact that there exist a varied range of rates. Keeping this in mind when comparing between clinics is crucial, since very high rates do not automatically translate into the birth of a large number of babies.

Thus, Intrauterine Insemination (IUI) results may be expressed using any of the following rates:

Pregnancy rate
Percentage of women that get a positive pregnancy test after the treatment. One should note that it can be measured by cycle (attempt), patient, year (average number of cycles done in that years), etc.
Ongoing pregnancy rate
Percentage of women that achieve pregnancy with the birth of a baby. It does not take into account if the baby is born alive or dead, or if he/she has some kind of malformation, pathology or disease.
Live birth rate
Percentage of women whose pregnancy ends with the birth of a live baby.

Cumulative success rate

One should understand that the pregnancy success rates of intrauterine insemination are cumulative. This means that, if you do not get pregnant on the first attempt, the chances of succeeding increase with the second attempt, and so on up until the 4th attempt.

A number of studies have proven that the success rates of IUI do not improve from the fourth attempt onwards. For this reason, further attempts would be useless. If pregnancy is not achieved after the fourth attempt, you should move on to IVF.

When it comes to examining the results, one should learn the difference between Artificial Insemination by Husband (AIH) and Artificial Insemination by Donor (AID). The chances of succeeding with donor sperm are slightly higher due to increased sperm quality.

Another aspect to bear in mind is that these rates are just approximate figures, and therefore they can vary from clinic to clinic, as well as depending on the particularities of each case, especially the age of the patient.

Cumulative rate of AIH

  • 1st IUI cycle: the pregnancy rate is 15-23%
  • 2nd IUI cycle: the pregnancy rate is 26-34%
  • 3rd IUI cycle: the pregnancy rate is 35-42%
  • 4th IUI cycle: the pregnancy rate is 40-60%

After the fourth attempt, the success rates of AIH (with the husband's sperm) can be as high as 60 percent.

Cumulative rate of AID

  • 1st IUI cycle: the pregnancy rate is 17-28%
  • 2nd IUI cycle: the pregnancy rate is 30-46%
  • 3rd IUI cycle: the pregnancy rate is 48-60%
  • 4th IUI cycle: the pregnancy rate is 60-75%

After the fourth attempt, the success rates of AID (with donor sperm) can be as high as 60-70 percent.

Pregnancy test

With a pregnancy test, we can find out whether IUI has been successful or not. It involves measuring the levels of beta-hCG hormone, which is released by the embryo after implanting into the uterus.

To prevent errors in the result, all patients are recommended to take this test within the next 15 days following insemination. If we take the test too early, the likelihood of getting a false positive or negative result is higher.

On the other hand, experts recommend that you take a blood test instead of a urine test, since they are more accurate and lead to a reduced number of errors. In any case, the final confirmation of pregnancy will not be available up until the gestational sac and the embryo are seen through ultrasound scan on week 6-7.

FAQs from users

Is there any concrete symptom indicating that artificial insemination has been successful?

By Dr. Paloma de la Fuente Vaquero MD, PhD, MSc (gynecologist).

No, the symptoms are the general ones of any pregnancy and usually appear approximately 15 days after insemination. Among the most common are nausea or vomiting, fatigue, sleep ... but do not differ from those produced by a natural pregnancy.

I have tubal patency in only one tube. Can I become a mother through IUI?

By Andrea Rodrigo BSc, MSc (embryologist).

As long as you have tubal patency in at least one Fallopian tube, the sperm and egg will be able to meet, allowing fertilization. For this reason, pregnancy is possible with IUI in spite of having one of your tubed blocked.

However, it should be noted that the success rates will be lower.

Artificial insemination after 40, does it work?

By Andrea Rodrigo BSc, MSc (embryologist).

The odds for pregnancy in women over 35-37 are low. For this reason, AI is not recommended at ages beyond 35.

From age 35 onwards, and especially at 40, a woman's ovarian reserve drops dramatically, while the chances for the eggs to have chromosomal alterations are higher.

The success rate of donor insemination in women younger than 40 is around 20-22%, while it drops to 13% in women aged 40. In the case of artificial insemination with husband's sperm, the percentage is 12-14% before age 40, and 9% in women aged 40 or more.

Can I get pregnant through IUI with endometriosis?

By Sara Salgado BSc, MSc (embryologist).

It depends on the location and how expanded the endometriosis is. If it is a mild-to-moderate case of endometriosis, then pregnancy could be achieved with this technique.

On the contrary, in the most severe cases, it is likely that the Fallopian tubes are blocked due to this condition, in which case the sperm would not be able to meet the egg. Also, it might have affected the endometrial lining, reducing the embryo's possibilities of attaching to it.

Should I move on to IVF after three failed IUI attempts?

By Andrea Rodrigo BSc, MSc (embryologist).

Although studies indicate an increase in pregnancy chances after the fourth attempt with artificial insemination, depending on the case, it is possible that, after three failed IUI attempts, your doctor refers you to IVF. This depends on each situation as well as on aspects such as the causes of infertility, the woman's age, the causes that led to failure of previous IUI attempts, etc.

Does IUI work in women with polycystic ovaries?

By Sara Salgado BSc, MSc (embryologist).

Yes, polycystic ovaries can cause infertility problems due to alterations in ovulation. However, with a mild ovarian stimulation cycle, normal menstrual cycles can be recovered and pregnancy achieved, either naturally or by IUI.

Can you choose the gender of the unborn child with IUI?

By Sara Salgado BSc, MSc (embryologist).

No. Since fertilization and subsequent embryo development occur inside the female's body, the embryos cannot be manipulated to examine their genetic content. So, in short, choosing the gender of the baby is not possible.

Suggested for you

Throughout this post, we have seen that the chances of pregnancy vary, amongst other reasons, depending on the type of insemination carried out: whether it is an AIH or an AID. Also, the cost of these types of AI is different, as you can read here: How Much Does Artificial Insemination Cost?

Also, we have made special emphasis on the importance of opting for Intrauterine Insemination (IUI) only in those cases where it is indicated. Otherwise, achieving satisfactory results would be highly unlikely. Want to learn more about the main indications? Click here: Artificial Insemination Indications – Why & When to Use It?

Our editors have made great efforts to create this content for you. By sharing this post, you are helping us to keep ourselves motivated to work even harder.


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FAQs from users: 'Is there any concrete symptom indicating that artificial insemination has been successful?', 'I have tubal patency in only one tube. Can I become a mother through IUI?', 'Artificial insemination after 40, does it work?', 'Can I get pregnant through IUI with endometriosis?', 'Should I move on to IVF after three failed IUI attempts?', 'Does IUI work in women with polycystic ovaries?' and 'Can you choose the gender of the unborn child with IUI?'.

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Authors and contributors

 Andrea Rodrigo
Andrea Rodrigo
BSc, MSc
Bachelor's Degree in Biotechnology from the Polytechnic University of Valencia. Master's Degree in Biotechnology of Human Assisted Reproduction from the University of Valencia along with the Valencian Infertility Institute (IVI). Postgraduate course in Medical Genetics. More information about Andrea Rodrigo
Dr. Paloma de la Fuente Vaquero
Dr. Paloma de la Fuente Vaquero
MD, PhD, MSc
Bachelor's Degree in Medicine from the Complutense University of Madrid, with a Master's Degree in Human Reproduction and a Doctorate in Medicine and Surgery from the University of Seville. Member of the Spanish Fertility Society (SEF) and the Spanish Society of Gynecology and Obstetrics (SEGO), she performs as a gynecologist specializing in assisted reproduction in the clinic IVI Sevilla. More information about Dr. Paloma de la Fuente Vaquero
License: 4117294
 Sara Salgado
Sara Salgado
BSc, MSc
Degree in Biochemistry and Molecular Biology from the University of the Basque Country (UPV/EHU). Master's Degree in Human Assisted Reproduction from the Complutense University of Madrid (UCM). Certificate of University Expert in Genetic Diagnosis Techniques from the University of Valencia (UV). More information about Sara Salgado
Adapted into english by:
 Sandra Fernández
Sandra Fernández
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

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