What is Intrauterine Insemination (IUI)?

woman discussing fertility options with her doctor

As part of your fertility treatment, your physician may discuss a procedure called intrauterine insemination (IUI). IUI entails the insemination of sperm through the cervix directly into the uterus, with the idea that having an increased concentration of sperm in the upper reproductive tract increases your chances for pregnancy. IUI is often used in patients with unexplained infertility, male factor infertility, and, when used with ovulation induction (medication used to trigger ovulation), can help patients with anovulatory cycles (menstrual cycles in which no egg is released for ovulation) to conceive. IUIs can also be beneficial in patients with vaginismus or sexual dysfunction as well as same-sex couples. 

Before starting an IUI cycle, your physician will likely perform several tests to assure that you are a good candidate for an IUI, as IUIs are not always the best first line treatment for all patients with infertility. This includes evaluating your uterus and fallopian tubes to ensure that there are no structural abnormalities that would prevent pregnancy. 

Hear from two fertility doctors on how IUI – intrauterine insemination works

Getting Ready for the IUI Cycle 

Prior to starting your IUI cycle, your doctor will review your screening bloodwork and imaging studies to make sure you are a good candidate for IUI. For patients with a tubal disease or severe male factor infertility, IUI may not be the best choice of treatment.

You and your doctor will also discuss whether to perform the IUI during your natural (unstimulated) cycle or with medications to assist with ovulation induction (OI). In a natural cycle, your doctor may recommend using ovulation prediction kits, which detect the luteinizing hormone (LH) surge that occurs just prior to ovulation, in order to determine when you are ovulating. Once the LH surge is detected, IUI is generally performed the next day. Your doctor may also want to perform an ultrasound on the day of the LH surge to confirm that a mature follicle is present prior to performing an insemination.

Your physician may also discuss a process called ovulation induction (OI). If ovulatory dysfunction is suspected as the reason for your infertility, ovulation induction, in conjunction with IUI, can increase your chances for pregnancy. The goal of ovulation induction is to encourage at least one follicle (the fluid-filled sac that contains an immature egg) to mature prior to ovulation. If you are undergoing ovulation induction, your doctor will give you fertility medication, which you may start taking at around day three or day five of your cycle, depending on your cycle length. The most common oral medications used for ovulation induction are Clomiphene Citrate and Letrozole. On occasion, injectable medications may also be used for ovulation induction.

At approximately day 11 or 12 of your cycle, your doctor will begin to evaluate for signs of ovulation. This may entail a transvaginal ultrasound to evaluate if your follicles are mature. Your physician might also perform luteinizing hormone (LH) surge testing as discussed in a natural cycle. When at least one follicle has a mean diameter of 18mm or greater, your physician may administer an injection of hCG (Human Chorionic Gonadotropin—a medication used to mature eggs) to induce ovulation 24-36 hours later.

It is generally recommended that the male partner who is providing a semen sample should abstain from ejaculation for two to five days prior to ovulation. On the day of your IUI, he will either produce a semen sample at home or in the doctor’s office by masturbation. (Alternatively, previously frozen sperm or donor sperm may be used). The semen is then processed and the sperm is concentrated. Similar to a pap smear, just before the IUI, a speculum is placed in the vagina so that the cervix is visualized. The sperm is then drawn up into a small insemination catheter that is then gently inserted through the cervix so that the sperm is injected directly into the uterus. The catheter and speculum are then removed.  After the IUI, you may experience some cramping and spotting. You may resume normal activities, including exercise and regular diet. Intercourse can also resume. Your physician will likely recommend a pregnancy test two weeks after the IUI to evaluate for pregnancy.