Intrauterine insemination, which is one of the most commonly used assisted reproductive treatments in case of failure of pregnancy by natural means, is a treatment based on injecting the sperms obtained after washing the semen samples taken from the male, directly into the uterus of the female. Its main purpose is to increase the chance of fertilization by increasing the number of spermatozoa reaching the fallopian tubes. 1
The quality of the sperms placed in the uterus with the help of a thin, long and flexible catheter has an effect on the success rate of this treatment. For this reason, the semen sample taken from the man is subjected to special processes and the most mobile and healthy sperms are injected into the uterus.2
Fertility drugs can be used while IUI, which is an assisted reproductive treatment consisting of extremely comfortable and simple steps, or treatment can be performed without any drug treatment.3
In order to maximize the success rate of IUI, couples who want to have a baby should be evaluated together, and sperm and egg quality should meet the ideal criteria. For this reason, there are some tests that need to be done before IUI treatment.
Intrauterine insemination treatment, medically known as IUI (intrauterine insemination), is an assisted reproductive technique in which laboratory-prepared sperm is placed directly into the uterus close to the time of ovulation.
The aim is to help sperm reach the uterus without having to pass through the vagina and cervical canal, and to place motile sperm closer to the egg.
In their 2024 systematic review, Chronopoulou and colleagues describe IUI as one of the commonly used fertility treatments. The review also explains that the fundamental principle of the method is to position sperm closer to the site where fertilization may occur.
IUI treatment does not guarantee pregnancy. The likelihood of success varies depending on factors such as the woman’s age, ovulatory function, tubal status, sperm quality, duration of infertility, and the underlying cause of infertility.
For couples researching IUI treatment in İzmir, the determining factor is not simply the city or the fertility center selected. The treatment must be planned for the appropriate patient group, with proper timing and suitable clinical evaluation.
IUI treatment may be considered for couples who are found suitable after evaluation. Factors such as the woman’s age, duration of infertility, ovulatory status, tubal patency, and semen analysis results are assessed together. Therefore, a diagnosis of infertility alone does not automatically lead to a recommendation for IUI.
Common indications for IUI include unexplained infertility, mild male factor infertility, and anovulatory infertility managed with ovulation induction.
The approach to unexplained infertility may vary depending on the patient. In the ESHRE 2023 guideline on unexplained infertility, IUI combined with ovarian stimulation is discussed as a treatment option for selected couples.
The NICE 2026 guideline states that in cases of unexplained fertility problems, if pregnancy has not occurred after a certain period, IUI may be discussed before IVF or alongside IVF as a potential treatment option.
Before planning IUI treatment, the most important considerations are ovulation status and whether the fallopian tubes are open. In IUI, fertilization is expected to occur within the body, usually in the fallopian tubes.
When both tubes are blocked or significant tubal damage is present, IUI is generally not considered an appropriate option. However, in cases where only one tube is blocked, the decision requires more careful evaluation. Depending on factors such as whether the other tube is open, the side of ovulation, age, and the overall clinical picture, IUI may be considered for selected patients.
For patients with ovulation disorders, the first step is to assess whether ovulation can be achieved. In some patients who achieve regular ovulation with medication, IUI treatment may be planned. Therefore, it is not accurate to assume that “IUI cannot be performed if there is an ovulation problem.” What matters is whether ovulation can be monitored and appropriately timed with treatment.
The ASRM Practice Committee’s opinion on natural fertility states that the fertile window is approximately a 5–6 day period ending on the day of ovulation.
For the male partner, the primary assessment is semen analysis. Sperm count, motility, and morphology are evaluated together.
IUI treatment may be considered in cases of mild sperm abnormalities. On the day of the procedure, the sperm sample is processed in the laboratory with the aim of preparing motile sperm for treatment.
However, if sperm count or motility is significantly reduced, the expected benefit from IUI may decrease. In such cases, other assisted reproductive techniques such as IVF or intracytoplasmic sperm injection (ICSI) may be considered.
IUI treatment is not the first-line option for every infertility condition. In some couples, alternative treatment methods may be more appropriate. In particular, other options may be considered in the following situations:
• Both fallopian tubes are blocked or there is significant tubal damage
• Severe male factor infertility
• Failure to achieve ovulation despite medical treatment
• Advanced maternal age and significantly diminished ovarian reserve
• Long-standing infertility
• Severe endometriosis
• Significant uterine abnormalities that may impair pregnancy
• Repeated unsuccessful IUI attempts
In cases of unilateral tubal blockage, the decision to proceed with IUI should not be automatic. If the other tube is open and the overall clinical situation is favorable, treatment can be individualized.
In patients with advanced age, diminished ovarian reserve, or prolonged infertility, time becomes a more important factor in treatment planning. In this group, rather than repeatedly attempting the same method, it may be necessary to reassess the treatment strategy at a certain point.
The WHO 2025 infertility guideline also emphasizes that infertility evaluation should identify the cause, consider the couple’s characteristics, and individualize treatment selection.
IUI treatment is a brief procedure scheduled according to the timing of ovulation. The basic principle is the placement of laboratory-prepared sperm into the uterus. The process generally proceeds through several stages.
Before IUI, the couple’s medical history is reviewed. The woman’s age, menstrual cycle, ovulatory status, tubal patency, and semen analysis results are evaluated together. This stage is necessary to determine whether IUI is an appropriate treatment option.
IUI is performed close to ovulation. Therefore, follicular development may be monitored by ultrasound. In some patients, the natural cycle is followed, while in others medication may be used to support follicular development. When necessary, a trigger injection is administered to help schedule the procedure more precisely.
On the day of the procedure, the sperm sample is processed in the laboratory. The aim is to isolate motile sperm and prepare them appropriately for insemination. The sperm used for IUI is always a laboratory-prepared sample.
The prepared sperm is introduced into the uterus using a thin, soft catheter.
Patients do not need to remain lying down for an extended period after the procedure. Studies indicate that post-procedure bed rest has not been shown to significantly improve IUI outcomes.
Patients are informed about when to perform a pregnancy test, which symptoms require medical attention, and any medication plans if applicable. Not every patient requires the same additional interventions, and the process is tailored according to the treatment protocol used.
IUI treatment is performed during the period closest to ovulation. Egg development is monitored, and the most appropriate timing is determined accordingly.
During monitoring, follicle size may be evaluated by ultrasound. LH testing may also be used when necessary.
The ASRM Practice Committee’s opinion on natural fertility states that the fertile window is a 5–6 day period ending on the day of ovulation, with pregnancy rates observed to be higher particularly during the two days preceding ovulation.
The NICE 2026 guideline also recommends timing artificial insemination around ovulation. Therefore, the most accurate information for patients is that IUI is not scheduled on a fixed menstrual cycle day. The optimal day is determined through ovulation monitoring.
Before IUI, the most important factor is ensuring that the procedure is scheduled at the correct time.
If a semen sample is to be provided, patients should follow the abstinence period and sample collection instructions recommended by the clinic. Any medications being used, previous surgeries, and existing medical conditions should be discussed with the physician.
If a medicated cycle is planned, treatment should not proceed without monitoring ovarian response. The development of multiple follicles may increase the risk of multiple pregnancy. Therefore, medication dosage, monitoring frequency, and the decision to proceed with insemination should be determined by the physician.
It is a common belief that prolonged bed rest is required after IUI; however, current evidence does not show that this significantly improves success rates.
Some patients may receive progesterone support after the procedure. Progesterone is a hormone involved in preparing the uterine lining for pregnancy. It is not routinely prescribed for every patient.
Patients should wait until the date recommended by their physician to perform a pregnancy test. Testing too early, especially if a trigger injection has been used, may lead to misleading results. If pain, heavy bleeding, fever, or any unexpected symptoms occur, the clinic should be contacted.
IUI success rates cannot be expressed as a single fixed percentage. Success depends on many factors, including age, cause of infertility, semen analysis results, ovulatory function, tubal status, treatment protocol, and the number of treatment attempts.
A woman’s age is one of the most important factors. As age increases, both the number and quality of eggs may decline. Treatment planning becomes particularly important after age 35, and time becomes an even more critical factor as age approaches 40.
Semen analysis also affects expectations for success. While IUI may be considered in cases of mild sperm abnormalities, other treatment options may be more suitable when sperm problems are more significant. Therefore, treatment decisions should be based on the couple’s overall clinical picture rather than a single test result.
Tubal patency is also important. In IUI, sperm is placed inside the uterus, but pregnancy can only occur if sperm and egg are able to meet within the fallopian tubes. Therefore, if there is suspicion of a tubal problem, it is not appropriate to establish expectations of success without proper evaluation.
IUI and IVF are different methods used to increase the likelihood of pregnancy. The main difference lies in where and how fertilization occurs.
In IUI, prepared sperm is placed inside the uterus. Fertilization is expected to occur naturally within the body, usually in the fallopian tubes. Therefore, the tubes must be open and the sperm must be capable of reaching the egg. In IVF, eggs and sperm are combined in a laboratory environment. The resulting embryo is then transferred into the uterus.
Egg retrieval is not performed in IUI treatment. The process generally involves ovulation monitoring, sperm preparation, and placement of sperm into the uterus. IVF treatment includes additional stages such as ovarian stimulation, egg retrieval, laboratory fertilization, embryo culture, and embryo transfer.
In some cases of unexplained infertility, IUI combined with ovarian stimulation may be considered one of the first treatment options. However, in other patients, factors such as age, duration of infertility, diminished ovarian reserve, tubal disease, or sperm parameters may make IVF a more suitable first choice.
The NICE 2026 guideline states that in unexplained fertility problems, if pregnancy has not occurred after 2 years, up to four cycles of IUI with gonadotropin ovarian stimulation may be considered before IVF, or IVF may be discussed as an alternative. The ESHRE 2023 guideline on unexplained infertility also emphasizes that treatment selection should be individualized according to patient characteristics.
For couples researching IUI treatment or IVF treatment in İzmir, the right question is not “Which is better?” but rather “Which treatment is more appropriate for my clinical situation?”
IUI treatment involves fewer procedural steps than IVF treatment. Egg retrieval is not performed, and embryos are not created in the laboratory. Instead, prepared sperm is placed into the uterus near the time of ovulation.
Because the treatment process is shorter, some couples may find it easier to manage. However, this does not mean that IUI is suitable for every couple or that it provides a high chance of success.
Another advantage of IUI is that sperm is delivered directly into the uterus without having to pass through the cervix and vaginal canal.
In some patients, the process can be planned close to a natural cycle. In others, medications that support follicular development may be used. In medicated cycles, follicle number and ovarian response should be monitored.
Chronopoulou E, Gaetano-Gil A, Shaikh S, Raperport C, Al Wattar BH, Ruiz-Calvo G, et al. Optimizing intrauterine insemination: a systematic review and meta-analysis of the effectiveness and safety of clinical treatment add-ons. Acta Obstet Gynecol Scand. 2024;103:1919-1932. doi:10.1111/aogs.14858.
Practice Committee of the American Society for Reproductive Medicine; Practice Committee of the Society for Reproductive Endocrinology and Infertility. Optimizing natural fertility: a committee opinion. Fertil Steril.2022;117(1):53-63. doi:10.1016/j.fertnstert.2021.10.007.
The Unexplained Infertility Guideline Group, Romualdi D, Ata B, Bhattacharya S, Bosch E, Costello M, Gersak K, et al. Evidence-based guideline: Unexplained Infertility. ESHRE; 2023.
National Institute for Health and Care Excellence. Fertility problems: assessment and treatment. NICE guideline NG257. London: NICE; 2026 Mar 31.
World Health Organization. Guideline for the prevention, diagnosis and treatment of infertility. Geneva: World Health Organization; 2025. Licence: CC BY-NC-SA 3.0 IGO.
It is one of the assisting reproductive techniques applied to couples who cannot have a baby by natural means. It is also called artificial insemination. IUI is basically in the form of injecting the sperm concentration obtained as a result of washing the semen sample taken from the male into the uterus, 1-2 days after ovulation is detected. The main goal of treatment is to increase the likelihood of pregnancy.
IUI is an assisted reproductive technique that can be applied very easily, consisting of several simple aforementioned stages, which also requires careful follow-up of ovulation.
IUI treatment alone does not increase the likelihood of twin pregnancy. However, in women who have ovulation problems, the maturation of more than one egg with the use of egg stimulant drugs may bring up the possibility of multiple pregnancies. Multiple pregnancy is not a targeted outcome of IUI. Therefore, the follow-up of egg development with ultrasound is extremely important.
In IUI treatment, sperms are released directly into the uterus, while in IVF treatment, eggs collected from women are combined with sperm obtained from the semen samples taken from men, in the laboratory environment, and the embryo is formed outside the womb. Then, the highest quality embryos among the embryos obtained are transferred into the uterus. These are the main differences between the two assisted reproduction techniques.
For the optimal success rate of IUI treatment , it is assumed that the minimum total motile sperm count should be at least 6 – 7 million. Increasing the number of motile sperm increases the success rate of intrauterine insemination.1
1https://www.fertstert.org/article/S0015-0282(08)02172-9/fulltext
IUI treatment can be an option for the couples with male-induced infertility problems, women with ovulation disorders, women with obstruction in one of their tubes, women with mild endometriosis problems, couples diagnosed with unexplained infertility.
In the success of the intrauterine insemination method, the reasons behind infertility, the timing of treatment and the age of women are extremely important variables. As women age, the success rate decreases. As a result of the researches, it was determined that the average success rate of IUI treatment was 13% among women under 35 years of age, 10% among ages 35-37, 9% among ages 38-40, and 3%-9% among ages 40 and older.1
1https://www.webmd.com/infertility-and-reproduction/what-is-iui-success
When both fallopian tubes are obstructed, when the egg reserve is inadequate and the quality of the eggs are lackluster, when the number and motility of sperm is severely low, in the presence of advanced endometriosis, IUI treatment is not recommended.
Note: This content is for general informational purposes only and does not replace diagnosis or treatment. A physician evaluation is required for personal diagnosis and treatment planning.
