IUI vs IVF

The fertility journey is not always easy as a couple or individual hopes. Sometimes it takes the assistance of a reproductive endocrinology and infertility specialist and fertility treatment to achieve a pregnancy.

Intrauterine insemination (IUI) and in vitro fertilization (IVF) are two separate fertility treatment options with various indications for use. While IUI and IVF are most commonly used for couples seeking to address infertility, they may also be used for other indications outside of infertility. For example, for individuals using a sperm donor to achieve pregnancy. 

This article explores IUI and IVF cycles in depth, including the key differences, the success rates of IVF and IUI, costs, and broader treatment considerations.

What is IUI?

IUI treatment, also known as intrauterine insemination, is a relatively simple procedure. A fertility specialist places sperm, which have been collected and processed in a lab, directly into the uterus via a flexible, thin catheter. Before sperm is inseminated, it is washed and purified in the lab to separate the sperm from the seminal fluid. 

When sperm is injected directly into the uterus, it bypasses the cervix altogether (which normally blocks >90% of sperm from entering the uterine cavity), and it decreases the distance the sperm has to travel to reach the egg. Together, this gives the sperm a better chance of successfully reaching an egg.

IUI starts with ovulation

Each month, in response to signals received from the brain, an egg grows and matures within the ovary in a fluid-filled sac called a follicle. During the middle of the cycle (around days 12-16, on average), the egg is ready to be released from the ovary, in a process called ovulation. Once the egg is released from its follicle, it is picked up by the fallopian tube, where, if present, sperm and egg can meet. 

An IUI procedure is timed to occur when the egg is being released. This way, sperm are ready and waiting for when the egg begins its journey along the length of the fallopian tube. Oftentimes, an injection or “trigger shot” is taken to ensure that ovulation occurs predictably. This allows your fertility specialist to plan the optimal time for your IUI procedure without guessing when ovulation is going to occur. 

Similarly, many patients will be prescribed medications to take at the beginning of their cycle (e.g., letrozole, Clomid) to recruit eggs to grow, mature, and ultimately ovulate. However, not all patients will need medications as part of their IUI cycle. Depending on your individual situation, it may be reasonable to plan for an IUI without any medications at all. 

The IUI procedure

The placement of sperm into the uterus usually only takes 5-10 minutes to complete. First, your fertility specialist will use a speculum to locate the cervix. Then a flexible, thin catheter is inserted through the cervix into the uterus. The sperm sample is injected through the tube and into the top of the endometrial cavity. The IUI process is generally painless, and anesthesia is not required. 

It can be helpful to have a full bladder, and if needed, ultrasound guidance can be performed. Within just a few minutes, the sperm will have reached the fallopian tubes where they will meet the egg. If fertilization and implantation occur, a pregnancy test is positive two weeks later.

After an IUI, you enter the “two-week wait” period. During these two weeks, it’s common for your fertility specialist to recommend that you avoid certain medications (e.g., ibuprofen) and activities (e.g., saunas, spas, hot tubs) while otherwise continuing with your usual activities, diet, and lifestyle. If you are not pregnant, it is medically acceptable to proceed with another IUI with your next cycle if you choose to do so. Your fertility specialist will be there to guide you in making decisions on the next steps.  

What is IVF?

In vitro fertilization (IVF) is a form of assisted reproductive technology (ART) in which sperm and eggs are combined in the embryology lab. In a normal monthly cycle, ovaries typically produce just one follicle and egg to grow, mature, and ovulate. However, along with the one egg that ultimately ovulates, several other eggs begin the early stages of growth before they’re ultimately discarded by the ovary. 

Therefore, for every one egg that ovulates, several other eggs are lost. This is the natural process of egg loss that occurs month after month, and explains why women will eventually deplete their egg supply during their lifetime (i.e., menopause). IVF takes advantage of this wasteful process by using medications to get all of those eggs to grow, along with medications to prevent them from ovulating, in a process known as ovarian stimulation. 

These medications are generally injectable and taken anywhere from one to three times a day, though some newer protocols utilize oral medications (e.g., Provera) in order to decrease the number of required injections.

Once the follicles have reached a certain size, the patient takes a final injection (“trigger shot”) which prepares the follicles for ovulation. Before the eggs are released from their follicles, your physician will remove them in an egg retrieval procedure. The egg retrieval is an outpatient procedure taking approximately 10-20 minutes and is performed under sedation. Most patients return home after about 1 hour of recovery, and the majority resume normal activities the following day.

While you are recovering, your eggs are counted in the embryology lab and prepared for insemination, which will happen later that day. Insemination, either via male partner sperm or donor sperm, can be achieved through conventional insemination or ICSI (intracytoplasmic sperm injection). 

Fertilized eggs will remain in culture for several days, maintained in a precise environment in the lab’s incubators, where they grow into embryos. After five to seven days of culture, any identified embryos can either be transferred fresh into the uterus, frozen, or biopsied and then frozen for preimplantation genetic testing (PGT). For patients freezing their embryos, they can then return in a future month (or year) for a frozen embryo transfer. 

What are the risks of IVF?

The IVF process is generally considered extremely safe, but like any medical treatment, it does carry some risks. Possible risks include side effects from fertility medications, with the most severe being ovarian hyperstimulation syndrome (OHSS). With modern-day IVF practices and improved IVF protocols and techniques, the risk of severe OHSS is incredibly low and can be prevented. 

Other possible complications are those from the egg retrieval itself such as the risk for bleeding, infection, or injury to neighboring pelvic structures. 

Is IUI or IVF right for me?

There are several key differences between IUI and IVF. Understanding these differences, along with guidance from your fertility specialist, will allow you to make an informed decision regarding your individual scenario. 

With IUI, fertilization of the egg takes place inside the fallopian tube within the body. This requires that you have at least one open fallopian tube in order for an IUI to have a chance at success. 

With IVF, the egg and sperm are fertilized in the embryology lab, creating an opportunity for couples who otherwise wouldn’t be able to, such as those with both fallopian tubes blocked or male factor infertility requiring advanced fertilization techniques.

Additionally, the embryo created with IUI cannot be genetically tested, while an embryo created via IVF can undergo genetic testing prior to transfer. The table below outlines additional comparisons to consider when exploring treatment with IUI vs IVF. 

IUI vs. IVF: Key differences at a glance

What are the success rates of IUI vs IVF? 

On average, IUI pregnancy rates are approximately 10–20% per cycle for women under 35, 8–10% per cycle for ages 35–40, and less than 5% per cycle for women over 40. Most IUI pregnancies occur within the first three to four attempts, with cumulative pregnancy rates of approximately 30–40% in favorable candidates. Success rates are lower than IVF and depend heavily on age, ovarian reserve, sperm quality, and diagnosis.

IVF offers higher success rates because fertilization and embryo development occur in a controlled laboratory setting, allowing for more targeted intervention. Recent U.S. data show live birth rates per egg retrieval using a patient's own eggs of approximately 48% for women under 35, 35% for ages 35–37, 23% for ages 38–40, and 8% for women over 40. Success rates can be further improved when embryos are frozen and transferred in a subsequent cycle.

When a chromosomally normal (euploid) embryo is identified through preimplantation genetic testing for aneuploidy (PGT-A), transfer success rates improve significantly, with implantation rates of 60–75% and live birth rates of approximately 55–70% per transfer, depending on maternal age, embryo quality, and uterine factors.

What about cost? 

IUI typically costs $2,000-$3,500 per cycle, depending on the cycle protocol, insurance coverage, the type of medications used, blood tests required, and follow-up needed.

While IUI can be less expensive and less invasive than IVF, the cost of multiple IUI cycles, if unsuccessful, may be similar to pursuing IVF. For those attempting IUI, fertility specialists typically recommend three to six rounds of IUI (depending on the individual clinical scenario) before choosing to progress to IVF.

The average cost of IVF in the United States is around $12,000- $25,000. This range reflects a number of variables that come into play, such as insurance coverage, cost of medications for various medication protocols, freezing embryos vs a fresh embryo transfer, and opting for additional treatments such as ICSI or PGT-A.

IUI or IVF: Which is right for you?

Many factors go into determining if IUI or IVF is right for you. If you have questions about IUI or IVF, or need help identifying if you need fertility assistance, Atlantic Fertility can help. Contact us or schedule an appointment with one of our fertility experts.

FAQs: IUI and IVF

Which one is better, IUI or IVF? 

Neither is universally “better.” The right treatment depends on your age, diagnosis, timeline, and budget. IUI is less invasive and less expensive, while IVF offers the highest success rates per cycle and is often more effective for many fertility conditions.

How much does three rounds of IUI cost? 

Three rounds of IUI typically cost $6,000–$10,500 total, depending on whether medications, monitoring ultrasounds, and lab work are included. Oral medication cycles are usually less expensive, while injectable medication cycles can cost more.

Can I conceive twins with IUI? 

Yes, twins are possible with IUI, especially when fertility medications stimulate the release of more than one egg. Twin rates vary, but are generally higher with medicated IUI cycles than with natural cycles. 

Why is IUI not as successful as IVF? 

IUI relies on fertilization happening inside the body, so egg quality, sperm function, and tubal health all play major roles. IVF bypasses many of these barriers by fertilizing eggs in the lab and selecting embryos for transfer.

What are the advantages of IUI vs IVF? 

IUI is less invasive, less expensive, requires fewer medications, and involves a simpler treatment process, making it a good first step for some patients. 

IVF offers the highest success rates per cycle, allows treatment of more complex fertility issues, provides options for embryo freezing and genetic testing, and can shorten time to pregnancy for many couples.

How many cycles of IUI should I try before moving to IVF? 

Many patients try three to six IUI cycles before considering IVF, since most successful IUIs happen within the first few attempts. Moving sooner to IVF may be recommended for women over 35, diminished ovarian reserve, tubal disease, or severe male factor infertility.

What is reciprocal IVF? 

Reciprocal IVF is a treatment option commonly used by female same-sex couples or couples with two partners who have ovaries and a uterus. One partner undergoes ovarian stimulation and egg retrieval, and those eggs are then fertilized with donor sperm. The resulting embryo is then transferred into the other partner’s uterus. 

This approach allows for one partner to contribute genetics and the other partner to carry the pregnancy, which can be a meaningful option for couples who want a shared reproductive experience.