Intrauterine insemination (IUI) is a non-surgical procedure that places prepared sperm cells into the woman’s uterus to produce a pregnancy. It is best to perform IUI in conjunction with hormonal stimulation of the ovaries to produce multiple eggs to increase chances of fertilization. IUI – also known as artificial insemination (AI) – is often the first choice for many fertility patients because of its simplicity and cost effectiveness compared to other fertility treatments.
IUI is often used for mild male factor infertility, for women with cervical mucus problems or mild endometriosis, and couples diagnosed with unexplained infertility. IUI coupled with donor sperm can also be used for lesbian couples and “choice moms” (single women who choose to become mothers) to achieve pregnancy.
There is a 5 to 20 percent chance of pregnancy when IUI is used, which increases when hormonal stimulation medication is added. Highly concentrated sperm are injected directly into the woman’s uterus, which is an easy and painless procedure. It is normal for a woman to undergo three to six IUI cycles before getting pregnant or moving on to more complex and expensive treatments, such as in vitro fertilization (IVF), which offer a higher chance of getting pregnant.
Generally, women under age 30 are the best candidates for IUI. The chance of IUI success drops for women in their 30s. For women over 40, IVF is often the first recommended step due to diminished egg quality caused by aging. Success rates are highest when the sperm have a healthy count, strength and motility in order to move from the uterus to the fallopian tubes.
Many patients choose to initiate treatment with IUI because it is less costly. However, IUI success rates are fairly low and couples often move on to IVF to become pregnant. Because of this, IUI is sometimes skipped to pursue IVF due to the superior 40 percent success rate of IVF. With the higher chance of success, IVF may be a quicker and less costly treatment option.
The advantage of IUI over other artificial insemination procedures – such as cervical and vaginal inseminations – is that the probability of an egg being fertilized is higher when a concentration of sperm enters the upper female reproductive tract. Cervical or vaginal insemination are generally not recommended because pregnancy rates are higher with IUI.
If stimulation medication that causes multiple egg production is used before an IUI procedure, there is a risk of multiple births. In these stimulated cycles, there is a 20 to 25 percent chance of twins, and a 5 percent chance of triplets. In addition, the stimulation medication can also cause ovarian hyperstimulation syndrome, which occurs in about 2 percent of IUI patients.