If you’re about to begin undergoing fertility treatments, there’s a chance you’ve asked yourself “does IUI even work?”. Maybe you’ve heard multiple success stories from IVF patients, but few from those who have conceived via IUI — or maybe you’re simply discouraged by the relatively low success rates (we’ll get into those below, but spoiler alert: IUI is unsuccessful more often than not). 

But IUI can work — it worked for me in 2018, when I conceived my twins. Though I had a lot of doubts going into the procedure, it ended up being the right choice for me. With that being said, it won’t necessarily be the best option for every case.

lesbian couple looking at their IUI results on a laptopUltimately, only you and your doctor can chart out your best course of treatment. But, if you’d like to learn more about how (and how often) IUI works, Jessica Ryniec, MD, a reproductive endocrinologist with CCRM Boston, sheds some light on its success rates, the factors that may affect these numbers, and what makes someone a good candidate for this treatment. 

First things first, how does IUI work?

“IUI is based on putting sperm high up in the uterus, closer to the egg at the time of ovulation,” says Dr. Ryniec. “There are different ways of doing the cycle: Some people will use their own cycles and call when they get a positive ovulation kit. Some people will do monitoring to watch their eggs growing and trigger ovulation with certain medications, and we time the IUI based on that. The goal is to try to make sure the sperm is there when the egg is being released.”

Dr. Ryniec likens the sensation of undergoing the procedure to a pap smear. “There’s a speculum exam which is placed into the vagina to visualize the cervix. Then a small, flexible catheter is placed through the cervix high up into the uterus, and the sperm is transferred into the uterus,” she explains. “Typically the sperm will be prepped ahead of time: If you have a male partner, they will come in and do their collection [and] we wash and spin it down to the best swimmers. Or, we use donor sperm.”

Part of IUI’s appeal lies in the fact that it’s far less invasive than IVF, but there may still be medication and frequent monitoring involved: Many patients take medications like Clomid or Femara, which stimulate ovulation and can increase the number of eggs produced to maximize your chances of fertilization (this increases your risk of conceiving multiples).

So, what are the IUI success rates?

IUI’s success rate can be up to around 20-25 percent for some patients, but that’s the best-case scenario and applies to people who are great candidates for the procedure. For many patients — for example, those in which significant male-factor infertility is at play, or those who are over 37 — that success rate is closer to 15 percent.

So yes, that seems low…discouragingly so, even. But, Dr. Ryniec points out that, when compared to a couple’s odds of conceiving without intervention, IUI can offer a significant boost in your chances of getting pregnant. For reference, after you’ve tried to conceive for a year (which warrants a diagnosis of infertility), you have just about a 4 percent chance of conceiving each month.

Remember, IUI’s success rates refer to each cycle; your odds of conceiving via IUI increase based on the number of rounds you attempt. 

What makes someone a good candidate for IUI?

Many people who cannot get pregnant without medical intervention (so perhaps a lesbian couple or a single woman) are excellent candidates for IUI and may opt to complete the cycle without medication.

People who do not ovulate regularly, but respond to oral medications that induce ovulation, are also good candidates, as are those who are facing mild male-factor infertility or unexplained infertility.

Be the expert in you.

Take the Quiz

Whatever your particular case looks like, you and your doctor can come up with a treatment plan that works for your case. That might involve trying three rounds of IUI before proceeding to IVF if they’re unsuccessful — some insurance policies will require three rounds of IUI before covering a round of IVF. 

couple celebrating their positive pregnancy test
But for other cases, IUI may not be the right option. For example, couples who are carriers of genetic disorders (such as cystic fibrosis) may opt for IVF (even in absence of fertility issues), as this allows them to genetically screen embryos before implantation. A patient who wants multiple children may choose to skip straight to IVF, as this route allows them to create multiple embryos for implantation down the line. And a patient with Fallopian tube blockages is not a good candidate for IUI, as the tubes need to be open for this procedure to be successful.

Patients and their reproductive endocrinologists can work together to determine which route makes the most sense based on the characteristics of their case and their preferences. 

Ultimately, there’s no one-size-fits-all solution where infertility is concerned. “It is a very individual thing, and we have these success rates that we can talk about, but it may be very different for each person’s individual situation. I always encourage [patients to] have that conversation with their provider [and ask] “what are my chances of success?” and also think about everything that goes into it, like how many kids ultimately you want to have, what benefits there might be to other treatment options — which all should be the conversation with a fertility doctor or provider,” says Dr. Ryniec. “We really want to individualize care.”

Zara Hanawalt is a freelance journalist and mom of twins. She's written for outlets like Parents, MarieClaire, Elle, Cosmopolitan, Motherly, and many others. In her (admittedly limited!) free time, she enjoys cooking, reading, trying new restaurants, and traveling with her family.