In vitro fertilisation (IVF) often receives most of the focus when discussing fertility therapy. On the other hand, couples tend to overlook simpler, less expensive, and less intrusive options like Intrauterine insemination (IUI) . While IVF is a very successful treatment option in Australia, it is not always the first option. For some couples, IUI may be the better alternative.

Significant takeaways

• IUI is a technique that injects sperm directly into the uterus soon before ovulation (the release of an egg from the ovary).
• IUI’s primary objective is to get the finest sperm closer to the egg before ovulation. Cycle success rates of 10% to 20% are common among Australian couples.

When to Transition from IUI to IVF

Many clinics recommend IUI for three to four cycles initially. However, repeated unsuccessful attempts may signal the need for a different approach. Key clinical indicators can help decide if IVF is more effective:

• Limited Ovarian Response: Producing only one dominant follicle during stimulation may lower the chances of fertilisation with IUI.
• Tubal Abnormalities: Blockages or structural issues in the fallopian tubes hinder sperm migration, making IVF—where fertilisation happens outside the body—a better option.
• Persistent Unexplained Infertility: When evaluations don’t identify a clear cause for infertility after several IUI cycles, it may be time to consider treatments that address these unresolved factors.

Talk with your fertility specialist about these indicators. Assessing ovarian reserve, tubal health, and overall reproductive status will help determine if transitioning to IVF could enhance your chances of conception.

• Fertility experts use IUI for no more than three or four cycles; beyond that, the odds of success decrease significantly. Doctors consider other procedures (such as IVF) at that time.
• Age, sperm count and morphology (shape), and fallopian tube patency are all variables that affect IUI success rates (i.e., no obstructions).
• Speaking with a reproductive endocrinologist about your health history (and that of your spouse, if relevant) and the findings of your fertility workup is an excellent approach to determining if IUI is a viable choice for you.

What is intrauterine insemination (IUI)?

In contrast to IVF , which may need many drugs and doctor visits, a fertility expert can perform a simple IUI treatment relatively easily. Dr Julie Lamb, MD, FACOG, a reproductive endocrinologist at Pacific Northwest Fertility and a member of the Modern Fertility Medical Advisory Board, explains that the primary purpose of IUI is to “move the best quality [sperm] closer to the egg and wait for the egg before ovulation.” Dr Lamb says that IUI treatment regimens would often change for individuals trying to conceive with a partner who also has ovaries, those trying to conceive independently, and individuals who do not have ovulatory (aka with ovulation) periods. Nonetheless, age, ovarian reserve (egg count), and family-building aspirations will significantly determine an individual’s treatment regimen. At its most basic level, IUI requires no drugs and just one doctor’s visit (your OB-GYN may even do tit):

How is IUI carried out?

A doctor may request that you track your ovulation at home using ovulation prediction kits (OPKs). You’ll visit the clinic if you notice an increase in luteinising hormone (LH), which coaxes an egg out of the ovary during ovulation. If you have a spouse who has sperm, they will gladly supply a semen sample.

What are additional procedures that are coupled with IUI?

As there are add-ons in the world of IVF, there are also add-ons in the world of IUI:

• Pre-operation drugs: Doctors may administer medications that stimulate ovulation before the surgery. Suppose an individual produces ovarian hormones (such as LH and follicle-stimulating hormone, or FSH) but is not ovulating. In that case, they will almost certainly receive ovulation-inducing medications such as clomiphene citrate. These medications may also be used in situations of unexplained infertility (when no anomalies in ovulation exist) and seem to increase conception rates (see here, here, and here).
• Gonadotropins: Gonadotropin is a fancy term for hormone injections such as FSH. They may increase follicular development and ovulation in women who are not ovulating but want to attempt IUI.
• Ovulation trigger shot: While it is possible to monitor spontaneous (or untriggered) ovulation at home using LH ovulation predictor kits, your doctor may prefer to use an ovulation trigger shot (which may be human chorionic gonadotropin, aka hCG, or Lupron) to control ovulation timing more precisely.
• Multiple insemination cycles: Some clinics use a single insemination session every cycle, while others use two. Although the data is fairly divided on whether double insemination has benefits, one possible downside is the expense of extra cycles.
• Progesterone supplementation: For a fertilised egg to establish a pregnancy, it must sink its heels into a well-developed endometrium (a.k.a. uterine lining), and the hormone progesterone mostly influences endometrial development. Doctors prescribe progesterone supplements after IUI to boost the possibility of implantation and prevent the uterine lining from shedding.

IUI is sometimes used as a first-line therapy, which is suggested before pursuing more difficult and expensive IVF treatments.

How effective is IUI? And what elements may affect success rates?

While some individuals often claim a success rate of 10% to 20% with IUI, the percentages for certain subgroups and settings may be much higher or lower. Yet, surprisingly, little agreement exists on the actual figures for these specific categories. Knowing where you stand on these parameters might help you develop more precise and individualised success rate estimates.

Age

Age

Age greatly affects IUI success, as studies show per-cycle pregnancy rates drop predictably with a woman’s age. Research indicates that approximately 19% of cycles result in pregnancy for women under 35, declining to 15% for ages 35–37, around 10% for ages 38–40, and roughly 7% for women over 40. These figures reflect the natural decline in fertility, helping patients and clinicians set realistic expectations when considering IUI treatments.

• 19% for those under the age of 35
• 15% for those between the ages of 35 and 37
• 10% for those between the ages of 38 and 40
• 7% for those over the age of 40

Factors affecting the sperm

IUI is often used to assist couples with sperm problems, such as a low total motile sperm count (the number of sperm that can move), a high proportion of sperm with aberrant morphology (sperm with atypical forms), or a high percentage of sperm with DNA damage. Unassisted conception results in some sperm being naturally screened out by the cervix and not reaching the uterus. IUI may help optimise the amount of sperm that reaches an egg during ovulation by bypassing the cervix, which may be especially beneficial in situations of low sperm count. Although the association between sperm count and IUI success rates is not linear, a higher sperm count typically results in a greater possibility of success. There are floor effects, implying that sperm counts less than 1 million have comparable success rates (i.e., the lowest success rates of all groups). Additionally, there are ceiling effects, implying that sperm counts greater than 9 million have comparable success percentages (i.e., the highest success rates of all groups). Small increases in sperm count can slightly increase success rates for anything in the centre. That same research of nearly 92,000 cycles was discussed previously. They examined the influence of total motile sperm count on IUI results (TMSC) and age. Clinical pregnancy rates were as follows for various sperm count bins:

• 4% for TMSC with a population of less than one million
• 5 per cent for TMSC between 1 and little about 2 million
• 10% increase in the number of TMSCs from 2 million to around 3 million
• 12% for 4 to little under 5 million
• 13% for a population of 5 million to a little under 6 million
• 14% for 6 to little about 7 million
• 14% for 7 to little about 9 million
• 17% for more than 9 million

Frozen vs. Fresh Sperm

Australian fertility clinics offer IUI treatments using fresh or frozen-thawed sperm. Fresh sperm, collected on the day of the procedure, usually has slightly higher motility. However, advances in cryopreservation enable frozen samples to perform nearly as effectively under optimal conditions.

Cryopreservation is valuable for donor insemination or when treatment scheduling requires a delay. Studies show that sperm stored for less than five years have survival rates after thawing of 80–85%. While the freeze-thaw process may slightly reduce motility or vitality, specialised laboratory techniques like advanced washing and preparation help maintain quality for successful IUI.

Choosing between fresh and frozen sperm depends on individual treatment needs. For example:

• Donor insemination programmes often use frozen samples for logistical flexibility.
• Patients needing coordinated treatment schedules or facing timing challenges may prefer frozen sperm.

Both options are supported by rigorous research and clinical experience, ensuring that IUI remains a reliable fertility treatment in Australia.

Cervical determinants

The cervix plays a significant role in conception. It is a tough barrier that sperm must pass through to reach the uterus and the egg. In cases where cervical factors may be contributing to infertility (i.e., cases of “hostile” cervical mucus that is less conducive to sperm travel), IUI may be particularly beneficial in comparison to other interventions such as intracervical insemination (ICI) or timed intercourse. Cervical factors can also influence fertility in some people.

Anatomy of the fallopian tube

A fallopian tube obstruction is one possible cause of infertility in women with ovaries. Sperm and eggs generally meet in the fallopian tube before moving to the uterus. Fallopian tube obstruction prevents this meeting. One or both fallopian tubes may be obstructed. The doctor might evaluate the obstruction with a hysterosalpingogram (HSG) technique . It is an X-ray of the uterus and fallopian tubes. Your doctor might not suggest IUI when both tubes have obstructions. While IUI delivers sperm to the uterus, the obstruction of the fallopian tube will prevent them from reaching the egg. As a result, it’s essential to rule out tubal obstruction before presuming IUI may benefit you. Suppose you’re contemplating IUI after attempting to conceive unsuccessfully for six to twelve months, depending on your age. In that case, your doctor may order an HSG as part of your infertility workup. Other tests might include blood tests and ultrasounds.

Endometriosis

Individuals with milder stages of endometriosis with free fallopian tubes and an egg count deemed “normal” for their age are ideal candidates for IUI. However, individuals with more advanced stages of endometriosis and blocked tubes are not. Individuals in this latter group should consider further treatment options, such as IVF.

Count of follicles

Most individuals will release one egg at ovulation in most (but not all!) of their cycles. When you use ovulation-inducing medications such as Clomid or Letrozole, your doctor will likely monitor you to determine how many follicles (the fluid-filled sacs that house and develop eggs) are growing as the likelihood of ovulating multiple eggs increases. According to several meta-analyses, the number of developing follicles is related to a greater likelihood of success in IUI. In contrast, the chance of pregnancy was 8.4% for cycles with just one growing follicle; it was about 15% for cycles with more than one developing follicle. There are potential dangers involved with targeting multiple follicles. Most significantly, many follicles increase the likelihood of carrying multiples, which has risks (like preterm birth, gestational diabetes, and preeclampsia).

How do IUI success rates compare to those of other methods?

Over the years, researchers have compared IUI to various alternative treatment options. While how IUI compares to other therapies depends on the subgroup studied, we may focus on its performance in unexplained infertility (where there is no definitive diagnosis).

Using intrauterine insemination vs IVF

In certain circumstances, a few cycles of IVF may achieve comparable success rates as IVF: Over 200 couples were randomly assigned one IVF cycle or three rounds of IUI + gonadotropins in one trial. The overall pregnancy rates for both groups were similar at the study’s conclusion . (The IUI group had greater success rates, but the difference was insignificant.) While IUI and IVF had significantly different live birth rates per cycle, an analysis of nearly 320,000 cycles in the United Kingdom found that IUI was substantially more cost-effective — meaning that when you consider the different success rates, the amount of money spent to achieve a live birth was markedly less for IUI than for IVF.

ICI vs. IUI

Intracervical insemination (ICI) fundamentally differs from intrauterine insemination (IUI) in the following ways. In IUI, sperm gets a VIP pass through the cervix and directly enters the uterus. However, with ICI, doctors inject sperm near the cervix. It implies that the sperm must overcome extra hurdles not present in IUI in ICI. Some studies (such as this one) demonstrate that success rates for IUI and ICI are equal, while others (such as this one) indicate an advantage for IUI over ICI.

IUI vs. scheduled intercourse

Knowing your fertile window and scheduling sex around it is one of the most effective ways to conceive. The jury is still out on whether IUI has greater success than timed intercourse in opposite-sex couples experiencing unexplained infertility, perhaps because of the scarcity of research intended to address this subject. The likelihood of pregnancy varies greatly according to how long someone has been trying to conceive. If someone has been attempting to conceive for more than six months without success, their odds of naturally conceiving are lower than they would be with IUI.

How do you determine if IUI is a viable choice for you?

The more information you have, the more equipped you are to make an educated and confident choice. The following are some topics to discuss with your fertility expert while you consider your options: If you’ve been attempting to conceive with a spouse who produces sperm without success, is there a known cause? It is a critical factor in determining whether to discard some choices or to make others more promising. For instance, IUI is probably not the best for unusually low sperm count. Making procedures like IVF a better bet in such situations. What are the success percentages for various treatment approaches at the same clinic? While the Society for Assisted Reproductive Technology (SART) provides annual data on IVF success rates, no such data exists for IUI. If the success rates for IUI and IVF seem comparable, IUI is much less expensive. It may be worthwhile to attempt a few cycles of IUI before pursuing more costly treatments. It takes us to the next point. What will your insurance cover for various procedures if you have it? Certain insurance companies will not cover IVF until undergoing several IUI cycles. It is something to consider when determining where to begin treatments. It’s also worth noting that it may be difficult to get fertility treatment coverage if you haven’t been trying to conceive for at least six to twelve months. Unfortunately, many plans are not structured to accommodate all possible pathways to parenting. If your work provides your insurance, it may be beneficial to inquire about fertility benefits or LGBTQ+-friendly insurance policies.

Evan kurzyp

Evan Kurzyp

Evan is the founder of Fertility2Family and is passionate about fertility education & providing affordable products to help people in their fertility journey. Evan is a qualified Registered Nurse and has expertise in guiding & managing patients through their fertility journeys.