What is IUI? A Guide to Intrauterine Insemination

Nicole Harris
Updated

Many couples struggling to conceive consider intrauterine insemination (IUI) as a fertility treatment option. During the minimally invasive procedure, sperm is inserted directly into the woman’s uterus, increasing the odds of successful fertilization. Here’s everything you need to know before signing up for IUI.

Who Gets an IUI?

One in eight couples struggle with infertility, or the inability to conceive after one year of trying (or six months of trying if the woman is over 35 years old). IUI is likely the first fertility treatment they try, since its cheaper and less invasive than in vitro fertilization (IVF). In fact, some insurance companies require multiple rounds of IUI before allowing IVF, says Dr. Tanmoy Mukherjee, a board-certified gynecologist and reproductive endocrinologist who works as a co-director of Reproductive Medicine Associates of New York. “We usually try IUI three or four times, then we move onto IVF if the treatment is unsuccessful,” he explains.

Oftentimes couples turn to IUI for issues involving the male partner’s sperm count. “A semen analysis dictates how much sperm is present, how the sperm are moving, and how they’re shaped,” says Dr. Mukherjee. “You want at least 10 million sperm per cubic centimeter (cc) in the ejaculate, and you want 40-50% of sperm to be moving properly. The shape of the sperm also correlates with the effectiveness of fertilization; you want 6% of the sperm to look normal or else the egg might not be fertilized properly.” Dr. Mukherjee explains that if there’s an issue with sperm count, motility (movement), or morphology (shape), doctors will consider IUI.

Aside from male factor infertility, other reasons couples choose IUI include:

  • Thick cervical mucus that prevents sperm from reaching the uterus

  • Infertility of an unknown cause

  • Use of donor sperm for whatever reason. For example, people may rely on donor sperm if they're in LGBTQ relationships, a single parent, suffering from poor sperm quality, or want to avoid genetic disease.

  • Endometriosis-induced infertility

Something to keep in mind: Women whose tubes are blocked aren’t candidates for IUI, since the egg can’t bypass a blocked tube. They will need IVF instead, says Dr. Mukherjee.

IUI Procedure: How is IUI Done?

To prepare for IUI, a woman will sometimes take medications like Clomid or letrozole to stimulate ovulation. According to Dr. Mukherjee, the optimal time to conduct IUI is prior to ovulation – specifically 12-24 hours before egg is released. The inserted sperm can survive for five days in the reproductive tract, so this timeline ensures that it’s ready for the egg’s introduction.

If you’re not using donor sperm, doctors need a semen sample from the intended father. It takes about an hour to prepare the semen for IUI. “You can not put semen directly into the uterus, so you have to first separate sperm from seminal fluid,” says Dr. Mukherjee. “Seminal fluid is rich in prostaglandins that cause extremely painful uterine contractions. That’s why we process semen so we only have sperm to inseminate with.”

The next step is mixing the sperm with a small amount of liquid and loading it into a syringe on a catheter. The doctor will place this inside of the vagina until it reaches the uterus, then dispense the sperm inside. “The actual insemination is like having a Pap smear,” says Dr. Mukherjee. You’ll be done with the procedure in a couple of minutes, and you don’t need medication.

Intrauterine insemination works by getting sperm closer to the egg than intercourse does. “When you're having intercourse, most of the sperm die in the vagina. The vagina is cooler and more acidic so 90% of sperm die there,” says Dr. Mukherjee. “But when you’re doing insemination, you put the sperm right into the uterine cavity. The uterus has normal body pH and body temperature, so more sperm survive and are more able to populate the reproductive tract.”

After an IUI procedure, the women should look out for early signs of pregnancy. An at-home pregnancy test should show results in about two weeks. If you experience a failed IUI, you can decide to try IUI again before resorting to other methods like IVF.

Side Effects of IUI

Common side effects of IUI include spotting and mild cramping. In very rare cases, a woman can develop an infection – but Dr. Mukherjee estimates the chances of infection are less than 0.5%. “If you feel warm, have an unusual vaginal discharge, or feel pain within 24 hours, visit the doctor. They will likely start you on antibiotics,” he says.

IUI Success Rate

IUI success varies based on maternal age (younger mothers have a higher success rate), sperm quality, and presence of fallopian tube damage. Taking fertility medications before an IUI procedure can increase the odds of conception.

Here are Dr. Mukherjee estimations on IUI success rates:

  • IUI for male-factor infertility: 8-10% success rate per cycle

  • IUI for tubal infertility: 5% success rate per cycle

  • IUI for unexplained infertility: 18-20% success rate per cycle

The chances of getting pregnant increase with each additional IUI cycle.

Cost of IUI

Since IUI is minimally invasive, it costs less than other fertility treatments options. Expect to pay about $300-$1,000 per cycle without insurance, but many healthcare plans cover some or all infertility treatments. Donor sperm is an additional cost – usually about $1000 per vial of sperm. Blood work, ultrasounds, and medications to induce ovulation also raise the price of IUI.

IUI vs IVF: What’s the Difference?

Although they’re both forms of artificial insemination, IUI vastly differs from in vitro fertilization (IVF). The IVF procedure involves collecting eggs from the ovary, mixing them with sperm in a petri dish, and inserting transplanting the resulting embryo into the uterus with a catheter. IVF can also be completed with donor eggs and/or donor sperm.

IUI has a greater success rate than IUI. If a woman is less than 35 years old, for example, 53.9% of IVF treatments with her own fresh eggs will result in live birth. IVF success rates vary based on maternal age, whether eggs are fresh or frozen, and if you’re using a donor. IVF is also more expensive than IUI; the IVF procedure costs about $12,000, plus an additional $3,000 - $5,000 for medication.