Natural-Cycle vs Medicated IUI: How Ovulation Tracking Changes the Insemination Plan

The kitchen counter tells the story: a row of urine test strips lined up by date, two of them with faint second lines, a phone alarm set for 6 a.m. so the morning sample is not missed. For many people, a first intrauterine insemination begins long before anyone enters a procedure room. It begins with watching.

Then the consultation adds a fork in the road. One version of the plan keeps the body’s own cycle and simply times the insemination to it. The other adds medicine to coax the ovaries, with more scans and an injection that sets the clock. Natural cycle IUI vs medicated IUI is less a contest between two treatments than two different ways of answering one question: when, exactly, will the egg be ready?

This explainer walks through how each plan tracks ovulation, who tends to be offered which, what the evidence actually shows about adding medicine, and what the two weeks after insemination usually look like.

Natural cycle IUI vs medicated IUI: what the two plans actually are

Intrauterine insemination (IUI) is a procedure in which a prepared sperm sample is placed directly into the uterus around the time an egg is released. The sperm is “washed” first, meaning the lab separates moving sperm from seminal fluid and debris so that only a small, concentrated volume goes through the cervix. Mayo Clinic describes the goal plainly: to put healthy sperm closer to the egg at the moment it matters.

A natural-cycle IUI, sometimes called unmedicated or unstimulated IUI, leaves the ovaries alone. The person ovulates as they normally would, and the team’s entire job is to detect that ovulation accurately and schedule the insemination against it.

A medicated IUI, also called stimulated IUI, adds ovulation-induction medicine. Ovulation induction is the use of medicines that encourage the ovary to develop and release an egg, or occasionally more than one. The team then monitors follicle growth by ultrasound. A follicle is the small fluid-filled sac in the ovary that holds a maturing egg. When the lead follicle reaches a mature size, a trigger injection of a hormone from the hCG or GnRH-agonist class prompts final egg release on a predictable schedule.

What changes between the two plans is not the insemination itself. Catheter, lab preparation, and the few minutes on the table are the same. What changes is the calendar: how many visits, what is being watched, and who decides the day. In a natural cycle, biology sets the date. In a medicated cycle, the clinician sets it, within limits that biology still enforces.

What actually happens on the day of insemination

Whichever plan brought you here, insemination day looks much the same, and it is quicker than most people expect.

The sperm sample is produced, or thawed if frozen donor sperm is used, and taken through the washing process in the lab. Cleveland Clinic notes that preparation separates and concentrates the most motile sperm into a small volume suitable for the uterus; unwashed semen contains prostaglandins that can cause painful cramping if placed directly in the uterine cavity, which is why the step is never skipped.

You lie on an exam table much as for a cervical screening test. A speculum is placed, and a thin, flexible catheter is passed through the cervix. The prepared sample is released into the upper uterus. Mayo Clinic describes the procedure as taking only a few minutes and usually feeling like mild cramping or pressure rather than pain, with no anesthesia needed. Some clinics ask people to rest on their back briefly afterward; the evidence on whether that helps is thin, and most teams allow normal activity the same day.

Before the catheter goes in, the team confirms timing. In a natural cycle that means a documented LH surge or an ultrasound showing a follicle about to release or already collapsed. In a medicated cycle it means the trigger injection was given on schedule, usually the day before, at an interval the team specifies.

The honest message for the day itself: the procedure is the easy part. Everything that determines whether sperm and egg meet was decided in the tracking that led up to it.

Natural cycle IUI timing: how ovulation tracking works without medicine

In an unmedicated cycle, the clinic is essentially eavesdropping on the body’s own hormonal conversation. Luteinizing hormone (LH) is the pituitary hormone whose sharp rise, the LH surge, instructs the mature follicle to release its egg roughly a day to a day and a half later.

Home urine LH tests detect that surge. The person usually begins testing several days before ovulation is expected, often with a stronger second line or a digital “peak” reading marking the surge. The team schedules insemination for the following day, when the egg is expected to be in the fallopian tube and still viable. Mayo Clinic describes this as the most common natural-cycle approach: test at home, call the clinic when the surge appears, come in the next day.

Many programs add transvaginal ultrasound, a probe scan that measures follicle diameter in millimeters, and sometimes a blood test for estradiol or LH. Ultrasound answers a question urine strips cannot: is there a dominant follicle at all, and is it the right size? A surge with no mature follicle, or a follicle that fails to rupture, can quietly spoil the timing even when the strip looked perfect.

Why this matters: a washed sperm sample survives in the reproductive tract for a limited window, and the egg is fertilizable for only hours after release. Natural-cycle IUI lives or dies on reading those signals correctly. People with regular, predictable cycles and clear surges tend to do this well. Those with irregular cycles, or whose LH tests give repeated faint or double peaks, are often the ones for whom the medicated route is suggested, not because their fertility is worse but because the clock is harder to read.

How a medicated IUI changes the tracking calendar

Add ovulation induction and the schedule flips from listening to directing. The medicine is typically started in the early follicular phase, the first days after a period begins, for a course of days set by the prescribing clinician. Then the monitoring begins.

A baseline ultrasound early in the cycle checks for cysts or a leftover follicle from the previous month. Roughly a week later, scans resume to watch follicles grow, often every day or two as they approach maturity. Blood tests may track estradiol, the estrogen produced by growing follicles, as a cross-check on how the ovaries are responding.

The pivotal decision is the trigger. Once the lead follicle reaches a size the team considers mature, a trigger injection of an hCG-class or GnRH-agonist hormone mimics the natural LH surge. Cleveland Clinic describes insemination then being scheduled within a defined window, commonly the next day, so that egg release and sperm placement line up almost to the hour. Some teams use a natural LH surge instead of a trigger even in a medicated cycle, if it arrives on its own.

Two things make this calendar different from the natural one. First, there are more appointments, and they cluster into a few intense days that can be hard to predict in advance. Second, the team can cancel. If the ultrasound shows too many mature follicles, most guidelines, including the NHS and professional-society guidance Mayo Clinic references, advise stopping the cycle rather than inseminating, because the multiple-pregnancy risk outweighs the benefit. A cancelled cycle feels like a loss; clinically, it is the safety system working.

IUI with letrozole or clomiphene vs injectable medicines: what each class does

People searching “which is better for IUI, clomiphene or letrozole” usually want a verdict. The more useful answer is to understand what each class does, because the choice is diagnosis-specific and belongs to the prescribing clinician.

Clomiphene is a selective estrogen receptor modulator, a medicine that blocks estrogen’s feedback signal in the brain. The pituitary responds as if estrogen were low and releases more follicle-stimulating hormone (FSH), pushing follicles to grow. Letrozole is an aromatase inhibitor, which temporarily lowers estrogen production itself, producing a similar rise in FSH by a different route. Letrozole was developed for breast cancer treatment and its use in ovulation induction is off-label in many countries; Mayo Clinic and Cleveland Clinic both describe it as a widely used option, particularly in polycystic ovary syndrome (PCOS), a hormonal condition in which ovulation is infrequent or absent.

Injectable gonadotropins are FSH, with or without LH, given directly. They are the most powerful stimulation and the hardest to steer, with higher rates of multiple follicles and of ovarian hyperstimulation syndrome.

Mechanism explains the practical differences. Clomiphene’s anti-estrogen effect can thin the uterine lining and reduce cervical mucus, though IUI bypasses the cervix. Letrozole has a shorter half-life, so follicle growth tends to be more selective, and the evidence summarized by major centers points to fewer twins. Gonadotropins require the closest monitoring of all.

Dosing, duration, and which class to use are individualized decisions. If one plan is suggested over another, ask why in terms of your own diagnosis; a good team will have a mechanism-based answer.

Who is usually offered natural-cycle IUI, and who is asked to wait

Unmedicated IUI makes most sense when the problem is not ovulation. Cleveland Clinic and the NHS list the typical candidates: people using donor sperm, single women and same-sex couples, couples where the male partner has mild reductions in sperm count or motility, and those with cervical factor infertility, where the cervix or its mucus impedes sperm. Some people with sexual difficulties that prevent intercourse, or where a partner’s medication or disability makes timing hard, are also offered it.

The common thread is a working ovulatory cycle. If the egg is already being released on a regular schedule, adding medicine adds risk and appointments without fixing anything that is broken. Several national guidance bodies, including those the NHS follows, specifically advise against stimulation when ovulation is already normal in these groups.

Who is asked to wait, or redirected? Anyone without confirmed open fallopian tubes. IUI depends on the egg reaching the uterus, so a tubal patency test, usually a dye X-ray or saline ultrasound, comes first. People with severe male-factor infertility are often advised that IUI is unlikely to help, because the washed sample needs enough motile sperm to make the approach worthwhile. Untreated thyroid disease, high prolactin, or unexplained bleeding are typically addressed before any cycle begins.

Age shapes advice too. Mayo Clinic and MedlinePlus both note that fertility declines meaningfully through the late thirties, and many teams limit how many IUI cycles they recommend before suggesting IVF. None of this is a judgment about who deserves treatment. It is triage toward the approach most likely to work for the actual diagnosis.

Who is usually offered a medicated cycle

Stimulated IUI exists for two broad situations, and they are worth separating because the logic differs.

The first is anovulation or irregular ovulation. In PCOS, hypothalamic amenorrhea with a mild cause, or cycles so unpredictable that LH testing fails month after month, the medicine is not a booster; it is the treatment. Ovulation induction creates the egg release that was not reliably happening, and IUI is sometimes layered on top when there is also a mild sperm or cervical factor. In pure anovulation with no other issue, many teams start with ovulation induction and timed intercourse before adding IUI at all.

The second is unexplained infertility, a label applied when semen analysis, ovulation testing and tubal assessment all look normal yet pregnancy has not happened. Here the goal of stimulation is different: to recruit one or two mature follicles instead of one, modestly raising the odds that at least one egg is fertilized. This is where the evidence is most contested and where judgment matters most. The NHS notes that routine IUI with stimulation for unexplained infertility is not universally recommended, because the gain over expectant management is uncertain and the twin risk is real.

Mild endometriosis sometimes falls into this second group. So does a history of natural cycles with poorly timed or mistimed inseminations.

Whichever situation applies, the team should be able to explain which of the two logics they are following. “Everyone gets stimulated” is not a diagnosis-based reason. “Your cycles are 45 to 60 days apart and we could not catch a surge in three months” is.

Natural cycle IUI vs medicated IUI at a glance

The table below summarizes the practical differences most people care about. It describes typical patterns reported by Mayo Clinic, Cleveland Clinic and the NHS, not guarantees about any individual cycle.

Feature	Natural-cycle IUI	Medicated IUI
What sets the timing	Your own LH surge, confirmed by urine test and/or ultrasound	Follicle size on ultrasound plus a trigger injection, or a monitored natural surge
Medicines involved	None, apart from an optional trigger in some programs	Oral ovulation induction (clomiphene or letrozole class) or injectable gonadotropins; often a trigger
Typical monitoring	Home LH tests; one or two scans in some clinics	Baseline scan, then serial scans and sometimes blood tests over several days
Number of mature follicles aimed for	One	One to two; cycle often cancelled if more develop
Multiple-pregnancy risk	Close to the background rate	Higher; highest with injectable medicines
Ovarian hyperstimulation syndrome risk	Essentially none	Low with oral agents, higher with injectables
Usual candidates	Regular ovulation with donor sperm, mild male or cervical factor, no partner	Anovulation or irregular cycles; selected unexplained infertility
Chance of cancellation	Missed or absent surge, unruptured follicle	Too many follicles, poor response, premature ovulation

A few readings of the table are worth stating out loud. The appointment burden of a medicated cycle is real and front-loaded. The follicle target is deliberately low; modern practice treats twins as a complication to avoid, not a bonus. And the natural-cycle row is not a lesser option. For the right diagnosis it is the recommended one, precisely because it adds nothing the body is already doing.

Is IUI better than trying naturally? What the evidence actually shows

It depends entirely on why pregnancy has not happened, and the honest answer is less flattering to IUI than many clinic websites suggest.

Where there is a physical barrier the procedure removes, the case is strong. Donor sperm has to get in somehow. If the cervix or its mucus is the obstacle, the catheter bypasses it. If intercourse is not possible, timing by insemination solves a logistical problem that no amount of waiting would. In these groups, IUI is not better than natural conception; it is the route to it.

Where ovulation is absent, the medicine does the work and insemination is secondary. Restoring ovulation is the treatment, and it clearly outperforms waiting for cycles that are not happening.

Where everything tests normal, the picture is murkier. MedlinePlus and the NHS both frame unexplained infertility as a situation in which continued timed intercourse for a defined period remains a legitimate option, especially for younger people with a short duration of trying. Mayo Clinic describes IUI as a reasonable first step but does not claim it beats expectant management across the board. Systematic reviews summarized in national guidance show that unmedicated IUI adds little over timed intercourse in this group, and that stimulated IUI adds some benefit at the cost of multiple pregnancy.

Per-cycle chances are modest for everyone and fall with age; no reputable source promises a figure for an individual. What the evidence supports is a question rather than a slogan: what, specifically, is this insemination fixing? If the team can answer that, IUI is probably the right tool. If the answer is “it might help,” ask what the alternative of waiting, or of moving to IVF, would look like instead.

What the next two weeks usually look like after either type of IUI

The interval between insemination and a pregnancy test is often called the two-week wait, and it is the same length in both plans. Mayo Clinic advises waiting about two weeks before a home pregnancy test, because testing earlier risks a false negative, or a false positive if an hCG trigger was used, since the trigger hormone is the same one the test detects.

In the first day or two, mild cramping and light spotting are common and usually reflect the catheter rather than anything happening with the egg. Normal activity, work and exercise are typically fine; the NHS and Mayo Clinic describe no required rest period.

In a medicated cycle, this is the window in which ovarian discomfort, bloating or breast tenderness from the medicines or the trigger can appear. Some programs prescribe progesterone support during this phase; progesterone is the hormone that prepares the uterine lining after ovulation. Whether it helps in IUI cycles is uncertain, and whether to use it is the clinician’s call.

Around days 10 to 14, a period either arrives or it does not. A missed period prompts the test. A positive result is confirmed with a blood test and, a few weeks later, an ultrasound to check location and number of pregnancies, which matters particularly after stimulation.

A negative result is not a verdict on the plan. Many teams review the cycle: was the surge or trigger timed well, did the follicle rupture, how did the ovaries respond? That review is where the natural-versus-medicated question often gets re-asked, and it is entirely reasonable to request it.

Stimulated IUI vs unstimulated IUI: the risks that differ

The insemination itself carries small risks in either plan. Cleveland Clinic lists mild cramping, spotting, and a low risk of infection from the catheter. These are the same whether or not medicine was used.

Multiple pregnancy is the risk that separates the two. In a natural cycle, twins occur at roughly the background rate because only one follicle matures. Add stimulation and the number rises, with injectable gonadotropins carrying the highest rates. Mayo Clinic and the NHS are explicit that twin and higher-order pregnancies increase the risks of preterm birth, low birth weight, pre-eclampsia and cesarean delivery. This is why mature-follicle counts trigger cancellation, and why oral agents are generally preferred over injectables as a first step.

Ovarian hyperstimulation syndrome (OHSS) is a condition in which stimulated ovaries swell and leak fluid into the abdomen. Mayo Clinic describes it as uncommon with oral medicines and more associated with injectables and hCG triggers. Mild forms cause bloating and discomfort; severe forms, which are rare, can involve rapid weight gain, significant abdominal swelling, breathlessness and blood clots, and require urgent care.

Medicines bring their own side effects. Clomiphene can cause hot flashes, mood changes and visual disturbances; letrozole, fatigue and dizziness; injectables, injection-site reactions and bloating. None of this is a reason to avoid treatment when it is indicated, but it is a reason the unmedicated route is preferred when ovulation is already normal.

The quieter risk is emotional and logistical: cancelled cycles, dense appointment schedules and the strain of daily injections. Teams that discuss this up front tend to have patients who cope better with it.

Where IVF fits, and what natural-cycle IVF actually means

IVF stands for in vitro fertilization: eggs are retrieved from the ovaries and fertilized with sperm in the laboratory, and a resulting embryo is placed in the uterus. It is a different procedure from IUI, not a stronger version of it. IUI relies on fertilization happening inside the body; IVF takes that step outside.

The practical distinction people most often miss is that IVF solves problems IUI cannot. Blocked tubes, severe male-factor infertility, and the need to test embryos genetically all require fertilization in the lab. Mayo Clinic and the NHS also describe IVF as the usual next step after a defined number of unsuccessful IUI cycles, with the number depending on age and diagnosis.

“Natural-cycle IVF” borrows its name from natural-cycle IUI but means something different: egg retrieval from the single follicle the body grows on its own, without stimulation medicines. It avoids OHSS and reduces medicine exposure, at the cost of retrieving one egg, or none if ovulation happens early. Modified natural and mild-stimulation protocols sit between this and conventional IVF. Whether any of these is “better” than standard IVF has no universal answer; the evidence reviewed by major centers shows lower per-cycle chances but a different risk and burden profile, and the choice depends heavily on ovarian reserve and prior response.

So the ladder is not natural IUI, then medicated IUI, then IVF for everyone. For some diagnoses the right first rung is IVF. For others, several natural-cycle IUIs are entirely appropriate. The treating team’s job is to match the rung to the reason.

What people often get wrong about natural cycle IUI vs medicated IUI

“Medicated is always stronger, so it must be better.” Stimulation treats absent or irregular ovulation. When ovulation is already normal, it mostly adds twin risk and appointments. Guidance followed by the NHS advises against stimulating these groups.

“A natural cycle means no monitoring.” It means no medicine. Monitoring is arguably more important, because the team has no trigger to control timing and must read the LH surge or follicle accurately.

“Twins would be a bonus.” Mayo Clinic and the NHS treat multiple pregnancy as a complication, with higher rates of prematurity and maternal complications. Cancelling a cycle for too many follicles is a safety measure, not over-caution.

“The trigger shot guarantees the timing.” It makes ovulation far more predictable, but follicles can still release early or fail to rupture. Teams often confirm with a scan.

“IUI babies are different from naturally conceived babies.” Fertilization happens in the body, exactly as in unassisted conception. The sperm is washed and placed higher; nothing about the egg or embryo is altered. Twins from stimulation carry the risks of twins, not of IUI.

“Letrozole is a cancer drug, so it is unsafe for fertility.” Its original indication is breast cancer, but short courses for ovulation induction have been studied extensively and are described by Cleveland Clinic as a mainstream option. Off-label does not mean unsupported.

“Lying still afterward or a particular diet changes the outcome.” Evidence for prolonged rest is weak, and no diet has been shown to alter IUI results. Normal activity is the usual advice.

“A negative cycle means the method failed.” Per-cycle chances are modest for everyone. A single cycle tells you little; a reviewed series of cycles tells you a lot.

Questions to ask your care team before choosing a plan

Good decisions come from specific questions. These are the ones that tend to surface the reasoning behind a recommendation.

• Which exact problem is this insemination meant to solve for us: sperm delivery, timing, ovulation, or something else?
• Is my ovulation regular on testing? If so, why would a medicated cycle be suggested over an unmedicated one, or vice versa?
• How will you confirm my fallopian tubes are open before we start?
• How will ovulation be detected: home LH tests, ultrasound, blood tests, or a combination? What happens if the surge is unclear?
• If medicine is proposed, which class and by what mechanism? What side effects should I expect, and what would make you switch classes?
• How many mature follicles would lead you to cancel the cycle, and what is your clinic’s typical cancellation rate?
• Will a trigger injection be used, and how long after it is the insemination scheduled?
• How many appointments should I expect, and can the clustered scan days be predicted in advance for work planning?
• How many cycles of this plan would you recommend before reviewing, and what would the next step be?
• Is progesterone support part of your protocol, and what is the evidence for it in IUI?
• What is your advice on home pregnancy testing timing, given the trigger can cause a false positive?
• If this cycle does not succeed, will we review the timing and ovarian response together?

Write the answers down. The reasoning that sounds obvious in the consultation room is hard to reconstruct three weeks later, and it is the same reasoning you will need when deciding whether to repeat, modify or move on.

When to call your doctor: red-flag signs during an IUI cycle

Most IUI cycles, medicated or not, pass without incident. Mild cramping on the day, light spotting for a day or two, and some bloating after stimulation are expected. The signs below are not, and each warrants a same-day call to the fertility team or urgent care.

• Severe or worsening abdominal pain, or pain that is one-sided and sharp, which can indicate ovarian torsion, a cyst complication or, after a positive test, ectopic pregnancy.
• Rapid abdominal swelling, sudden weight gain over a day or two, nausea with vomiting, or passing very little urine after a medicated cycle. Mayo Clinic lists these as features of ovarian hyperstimulation syndrome that need prompt assessment.
• Shortness of breath, chest pain, or a swollen, painful calf. Blood clots are a rare but serious complication of OHSS and of early pregnancy.
• Fever, chills, or foul-smelling vaginal discharge after insemination, which may signal infection.
• Heavy vaginal bleeding, meaning soaking through a pad every hour, at any point in the cycle.
• Visual changes such as blurring, flashes or spots while taking clomiphene; the team may wish to stop or change the medicine, a decision that is theirs to make.
• Fainting, dizziness on standing, or a racing heartbeat.
• After a positive pregnancy test, any bleeding or pelvic pain, particularly with shoulder-tip pain.

Do not stop, start or adjust any prescribed medicine on your own in response to symptoms; call first. Teams would far rather field an unnecessary call than miss an early complication. If you cannot reach the clinic and symptoms are severe, use emergency services. Every treatment decision, including whether to continue, cancel or modify the cycle, rests with the clinicians who know your case.

Frequently asked questions

Is IUI better than trying naturally?

Only when it fixes a specific barrier. IUI clearly helps when donor sperm is needed, the cervix impedes sperm, intercourse is not possible, or ovulation is absent and medicine restores it. For unexplained infertility with normal tests, the evidence shows unmedicated IUI adds little over timed intercourse, and medicated IUI adds modest benefit with higher twin risk. Ask your team what the insemination would specifically solve.

Which is better for IUI, clomiphene or letrozole?

Neither is universally better; the choice depends on diagnosis. Letrozole is often preferred in polycystic ovary syndrome and tends to produce fewer multiple follicles, while clomiphene has a longer track record but can thin the uterine lining. Both work by raising follicle-stimulating hormone through different mechanisms. The prescribing clinician weighs your ovulation pattern, prior response and side-effect profile.

What is the difference between stimulated IUI vs unstimulated IUI?

Unstimulated, or natural-cycle, IUI times insemination to your own ovulation using LH tests or ultrasound, with no ovarian medicines. Stimulated IUI adds ovulation-induction medicines and closer ultrasound monitoring, usually with a trigger injection to schedule egg release. Stimulation carries higher risks of multiple pregnancy and, with injectables, ovarian hyperstimulation syndrome.

How is natural cycle IUI timing worked out?

Most clinics ask you to test urine for the LH surge daily from several days before expected ovulation, then schedule insemination for the day after the surge appears. Many add an ultrasound to confirm a mature follicle is present. Mayo Clinic describes this surge-plus-next-day pattern as the standard natural-cycle approach; exact timing is set by your team.

Can I do IUI without medication if I have PCOS?

Usually not as a first approach, because PCOS typically involves infrequent or absent ovulation, which makes a natural LH surge unreliable or missing altogether. Ovulation induction is generally the treatment that makes insemination possible. Some people with PCOS do ovulate regularly, and in that case an unmedicated cycle may be considered; the decision depends on your cycle history and the team’s assessment.

What does IVF stand for, and how is it different from IUI?

IVF stands for in vitro fertilization. Eggs are retrieved from the ovaries and fertilized with sperm in the laboratory, and an embryo is then placed in the uterus. IUI places washed sperm into the uterus and relies on fertilization happening inside the body. IVF is used when tubes are blocked, sperm problems are severe, embryo testing is needed, or IUI cycles have not succeeded.

Is natural cycle IVF a better option than regular IVF?

Not as a general rule. Natural-cycle IVF retrieves the single egg the body grows without stimulation, avoiding ovarian hyperstimulation syndrome and most medicines, but it yields one egg or none per cycle and has lower per-cycle chances than conventional IVF. It may suit people with low ovarian reserve, prior poor response or reasons to avoid stimulation. The choice belongs with the treating team.

Why would a medicated IUI cycle be cancelled?

The most common reason is too many mature follicles on ultrasound, which raises the risk of twins or triplets to a level most guidelines consider unacceptable. Cycles are also cancelled for poor response, a cyst at baseline, or ovulation that occurs before the planned insemination. Cancellation is a safety decision rather than a sign the treatment is not working.

How soon after medicated IUI can I take a pregnancy test?

Mayo Clinic advises waiting about two weeks after insemination. Testing earlier risks a false negative, and if an hCG trigger injection was used, the test can read falsely positive because it detects the same hormone. Your clinic will usually give a specific test date and may confirm a result with a blood test.

Do IUI pregnancies carry different risks for the baby?

The insemination itself does not alter the egg, sperm or embryo; fertilization happens inside the body as in unassisted conception. The added risk comes from multiple pregnancy after ovarian stimulation, which raises rates of preterm birth and low birth weight. That is why teams aim for one or two follicles and cancel cycles that exceed that target.

References

• NHS: Intrauterine insemination (IUI)
• Cleveland Clinic: IUI (Intrauterine Insemination)
• MedlinePlus: Infertility

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.