Intrauterine Insemination (IUI)
Intrauterine insemination (IUI) is one of the simpler, “low-tech” treatments for infertility and the starting point for many individuals and couples who are having difficulty with conception on their own.
Low-tech fertility treatments like IUI aim to develop one to four eggs, with fertilization taking place within the patient’s body instead of in the laboratory setting.
Common indicators for IUI
Patients who have been diagnosed with unexplained infertility, mild male factor infertility, a cervical factor, or irregular or absent ovulation are often good candidates for IUI.
The goal of this treatment is to increase the number of sperm that reach the Fallopian tube and subsequently increase the chance of fertilization. IUI provides the sperm an advantage by giving it a head start but still requires the sperm to reach and fertilize the egg on its own. Depending on your fertility diagnosis, IUI can be coordinated with your normal cycle or with fertility medications.
A physician may also recommend IUI in cases where a woman or couple needs donor sperm. Before you and your doctor make the decision about whether or not IUI is right for you, you will undergo standard infertility testing.
Intrauterine insemination (IUI) process
Step 1A: Ovarian stimulation | Medications
The main goal of this phase is to induce ovulation with common medications like Clomiphene citrate (Clomid, Serophene). Clomid facilitates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which stimulates the ovaries to produce eggs and the ovarian hormones estradiol (E2) and progesterone (P4). Patients can expect to orally take Clomid for 5 to 7 days typically starting on day 3 of a their menstrual cycle. It’s best to take the medications daily at bedtime, or as instructed by the physician. Additionally, the physician may prescribe an Ovidrel injection prior to the IUI to trigger the egg release.
Step 1B: Ovarian stimulation | Monitoring
The physician will monitor egg development with E2 and LH hormone tests and ultrasound scans of the ovaries. Increased levels of estrogen are a good indicator of follicular development. Additionally, ultrasounds help physicians see the thickness of the uterine lining and ovaries and the number of follicles within them. Because timing is key with insemination, these tests will reveal when eggs are mature and ready for insemination.
Step 2: Sperm washing
While ovary stimulation occurs, our andrologists also turn their attention to sperm samples to perform a procedure commonly known as sperm washing to identify the most healthy, motile sperm. The procedure begins by placing a test tube containing the prepared sperm sample in a centrifuge to collect a concentrated sperm “pellet” at the bottom of the test tube. The andrologist then removes the seminal fluid and drops a sperm preparation media on top of the sperm. The media helps stimulate high motility and support capacitation. The most active sperm will swim up into the media, collecting the healthiest, most motile sperm sample.
Step 3: Insemination
Our physicians generally perform IUIs one and a half days after the trigger injection, which sets ovulation in motion. The exact timing of insemination is not critical to the exact time of ovulation because both the sperm and the egg remain viable in the assigned female genital tract for many hours. A single IUI is usually performed when a patient is using fresh sperm. If a patient is using a frozen sperm sample, likely one or two IUIs can be performed.
Step 4: Implantation
Following the IUI, the patient will take daily supplemental progesterone — usually in the form of a capsule inserted into the vagina twice a day — to support the endometrial lining of the uterus and implantation of the embryo.
Natural rate of conception varies from 5 to 25 percent based on maternal age
For couples who have no difficulty achieving a pregnancy, the natural chance of pregnancy per month of ovulation is largely dependent on the age of the woman. For women in their early 30s or younger, the natural pregnancy rate is about 20 to 25 percent per cycle. This drops off significantly through her mid-to late-30s; by her early 40s, the chance of pregnancy is about 5 percent per cycle. This age-related decrease is primarily due to a decline in the quality of the eggs within the ovaries.
Intrauterine insemination pregnancy rates by age
For most couples having difficulty achieving a pregnancy their chance of achieving a pregnancy is not zero, it is just lower than the average rate of conception—unless both Fallopian tubes are completely blocked, there is no sperm, or the woman never ovulates. Ovulation induction (or superovulation) with IUI helps patients to achieve pregnancy rates closer to the natural per cycle chance of pregnancy for women in their age group who do not have infertility (see fig 1).
Since the chance of pregnancy per treatment cycle is modest, it may take more than one cycle of IUI treatment in order to achieve a pregnancy. However, after three to four cycles of IUI treatment, if pregnancy has not occurred, it may be advisable to move to more advanced treatments such as in vitro fertilization (IVF).
Because the chance of pregnancy with IUI is low for women over the age of 40, we generally recommend fewer IUI cycles before progressing to IVF. After 40, patients should consider IVF earlier in the treatment timeline.
Intrauterine insemination pregnancy rates by diagnosis
In addition to age, a couple’s prognosis for success with IUI depends on their diagnosis (see figure 3). IUI is most successful in couples where the primary cause of infertility is an ovulatory problem such as polycystic ovary syndrome (PCOS). In these cases, the treatment comes closest to restoring the natural per cycle pregnancy rate.
For several reasons IUI is also quite successful for the treatment of mild male factor or unexplained infertility, although the success rates are slightly lower than for those couples where ovulatory dysfunction is the only problem.
Intrauterine insemination is less successful if the cause of infertility involves decreased egg quality, diseased Fallopian tubes, or endometriosis. IUI treatment cannot improve the quality of the eggs within the ovaries or repair damaged anatomical structure. As with advanced age, it may be advisable to move to IVF earlier in the treatment timeline with these diagnoses.
The Fallopian tubes are the site for fertilization before the embryo makes its way to the uterine cavity for implantation. If the Fallopian tubes are damaged, fertilization may not occur. If one Fallopian tube is blocked, it may be due to inherent disease involving both Fallopian tubes; even if the other Fallopian tube is open, it may not be able to provide the appropriate nurturing environment for fertilization and early embryo growth to take place.
Intrauterine insemination and multiple pregnancies
A major concern for couples undergoing any fertility treatment is the risk of a multiple pregnancy. Shady Grove Fertility pays close attention to patients undergoing stimulation by closely monitoring follicular development to keep the multiple pregnancy rates low (see fig. 4).