While most patients think of IVF when they think of assisted reproductive technology (ART), reproductive specialists consider many treatment options depending on the cause and circumstances of a patient's infertility. For some patients, intrauterine insemination (IUI) is an avenue worth exploring.
Intrauterine insemination involves clinicians placing sperm directly into the uterus to help promote pregnancy. This approach aims to give sperm a better chance of reaching and fertilizing an egg. Physicians should understand the basics of this technology and which patients may be best suited for it.
Basic Steps of Intrauterine Insemination
Intrauterine insemination mimics the natural conception process, but delivers sperm past the cervix and into the uterus near the time of ovulation, explains the American Society for Reproductive Medicine. This placement shortens the sperm's journey to the fallopian tubes, improving its odds of encountering a recently released egg.
A patient must be ovulating for intrauterine insemination to be effective. This can be achieved through the use of ovulation-stimulating medications or by timing normal ovulation. Once ovulation is confirmed, sperm is typically collected from a partner or donor in the clinician's office. Next, the sample is washed in the lab to remove the sperm from the seminal fluid.
Once the sample is prepared, a clinician inserts a catheter through the ovulating patient's cervix and injects the concentrated sperm into their uterus. This process only takes a few minutes and may result in minimal cramping and discomfort for the patient.
Growing Success Rates
Intrauterine insemination generally produces lower success rates than IVF. Its efficacy depends on a number of factors, including a patient's age; the main determinant is the underlying cause of infertility.
Successful outcomes of intrauterine insemination have increased over time even though the process itself has not significantly changed. Thanks to advances in stimulation protocols, sperm preparation and ovulation monitoring, success rates for intrauterine insemination have grown from 5 percent to 20 percent per cycle during the past several decades, according to research published in the European Medical Journal.
Two studies from the last five years suggest that intrauterine insemination can be very effective for certain patients. The first, a randomized controlled trial conducted in New Zealand and published in The Lancet, looked at the effects of this ART technique on heterosexual couples with three to four years of unexplained infertility. About half of these couples underwent expectant management — also known as watchful waiting — while the others received three cycles of intrauterine insemination. Researchers noted a live birth rate of 31 percent in the intrauterine insemination group compared to 9 percent in the group who received expectant management.
In another randomized controlled trial published in Facts, Views and Vision, researchers in the Netherlands found stimulated intrauterine insemination with clomiphene citrate to be a superior first-line therapy for unexplained subfertility compared to low-dose follicle-stimulating hormone.
The Role of Ultrasound
Ultrasound is one of the factors linked to the rising success rates of intrauterine insemination. According to a study from the Journal of Obstetrics and Gynaecology of India, using ultrasound, including 3D and 3D Power Doppler, enables assessment of the follicular volume, perifollicular resistance index, and perifollicular vascularity index, all of which influence conception rates. Access to this valuable information can lead to improved pregnancy rates.
Research published in the Archives of Gynecology and Obstetrics evaluated the influence of ultrasound guidance on pregnancy rates during 387 gonadotropin-stimulated intrauterine insemination cycles performed for unexplained infertility. Researchers divided patients into two randomized groups: 180 participants received ultrasound-guided intrauterine insemination, while 207 underwent the ART approach without ultrasound guidance. The investigators discovered that pregnancy rates were higher in the ultrasound-guided intrauterine insemination group (17.2 percent) compared to the nonguided intrauterine insemination group (10.1 percent).
Researchers also noted that pregnancy rates were more likely to be higher within the ultrasound-guided group when imaging was performed by a senior physician. This suggests that when it comes to the use of ultrasound in IUI, experience is key for achieving favorable results.
Identifying the Best Candidates
Intrauterine insemination can be a viable option for patients with a variety of fertility challenges. For instance, the Facts, Views and Vision study from the Netherlands suggests that intrauterine insemination should be the first choice of treatment for unexplained male factor subfertility.
Others who may be eligible for intrauterine insemination include patients with:
- Cervical stenosis or cervical scarring due to surgery.
- Cervical mucus challenges.
- Unexplained infertility.
Patients with male partners with retrograde ejaculation, erectile problems or an abnormally formed urethra may also be good candidates for this ART approach, as are patients who wish to conceive using donated sperm, including single women and same-sex couples.
Conversely, this technique is not recommended for certain patients, including women who have a history of pelvic infections or severe disease of the fallopian tubes.
IUI for Patients With Endometriosis
Whether patients with endometriosis can benefit from intrauterine insemination depends on the severity of the disease case. This form of ART can be effective in cases of mild to moderate endometriosis, but is generally not recommended or offered to patients with severe endometriosis.
One study published in BioMed Research International found that a combination of corrective surgery, controlled ovarian hyperstimulation and intrauterine insemination was more effective in achieving pregnancy for endometriosis patients than surgery followed by simple monitoring. When the same surgery was coupled with IVF, it was found to be less effective at achieving pregnancy.
While intrauterine insemination may not work for every patient, it is a viable option for some cases of infertility. As with other assisted reproductive technologies, intrauterine insemination is associated with a higher chance of multiple pregnancies. Otherwise, intrauterine insemination carries few risks and is considered a safe technique for the majority of patients with infertility. Clinicians should consider this approach when discussing ART options with their patients.
