Intrauterine insemination versus in vitro fertilization:  What is the role of IUI in modern fertility practices?

As fertility practices mature and in vitro fertilization (IVF) becomes more efficient, safer, and successful, the hot topic of conversation centers on the benefits of intrauterine insemination (IUI) as a first line treatment. In the past, IVF was not significantly more successful than IUI, especially in patients with diminished ovarian reserve. Now with improved technologies such as freezing embryos and preimplantation genetic screening (PGS), we are beginning to see a wider and more significant gap in success rates between IVF and IUI cycles.

A study published in May 2017 showed that over a five-year period, 35 percent of women of all studied age groups gave birth with IUI treatment versus 53 percent of women with ART treatments over the same time period. Although 53 percent is a much larger number, 35 percent still were able to achieve live birth without undergoing IVF. This still gives relevancy to IUI as a treatment, especially in a properly chosen patient population.

Choosing the Right Treatment

In general, IUI can be performed with and without ovarian stimulation, and can be achieved with oral agents and injectable hormones. The goal of IUI is the ovulation of one or more follicles to increase the per cycle pregnancy rates to match normal controls. On the other hand, IVF is almost exclusively done with high-dose injectable medications, requires anesthesia, and places significant physical/financial burden on the patient given the complexity of laboratory procedures. Although there are clear differences between the two treatment processes, there are associated complications with both procedures that make both of them risky to the patient.

One of the main concerns in modern fertility practices is the birth of multiples. IUI does not seem to be associated with increased rates of multiple births as compared to standard IVF cycles. However, most of this data is old and with the introduction and acceptance of genetic screening of preimplantation embryos, we are seeing higher and higher rates of elective single embryo transfer cycles – leading to significantly decreased rates of multiple gestations in IVF treatments. The modern practice of IVF as compared to 5-10 years ago most likely has a significantly decreased rate of multiple gestations and new randomized clinical trials prove this benefit of single embryo transfer.

Another consideration in the choosing of an optimal treatment pathway involves a cost analysis. The FORT-T trial, an important randomized, controlled fertility trial, showed the benefit of foregoing an IUI cycle and moving directly to IVF. The study argued that success rates are significantly lower in IUI cycles than IVF in patients ages 38 to 42. In fact, many of these patients required IVF after multiple failed IUI cycles. In the first arm of IVF, there were 36 percent less treatment cycles than the arm where IUI was attempted first. Given that the cost of multiple IUI cycles approaches the cost of a single IVF cycle, the conclusion can be made that in certain patient populations (specifically older and diminished ovarian reserve patients) there may be benefit to moving directly to IVF based on costs.

Reducing the Burden of Fertility Treatment Cycles

Finally, infertility is a disease and has been recognized as one by the World Health Organization since 2009 and the American Medical Association as of June 2017. Beyond this fact, infertility is an emotionally charged diagnosis and the treatment itself can be physically and emotionally draining. Drop-out rate is a real phenomenon in fertility treatment and the negative effect is that couples that could have been helped never had the opportunity to benefit from successful treatment. The FORT-T trial showed improved pregnancy rates with fewer cycles, demonstrating that one of the most important arguments for moving straight to IVF is this decrease in treatment time and, consequently, a decrease in drop-out rates. IUI is, without question, a useful treatment modality in a properly selected patient. Ultimately, proper counseling and realistic expectations must be discussed with the patients prior to the selection of any fertility treatment.