IUI in Markham: What the Best Clinics Do Differently

Key Takeaways

• Follicle monitoring frequency and target size, commonly 18 to 22mm, directly affect timing accuracy, not just whether monitoring happens at all.
• Clinics time insemination off either a trigger shot or a natural LH surge, and the choice is individualized to each cycle, not a fixed default.
• Follicle count at trigger is a safety decision as much as a success one, since too many mature follicles at once raises multiple-pregnancy risk and can lead a clinic to adjust or cancel the cycle.
• Peer-reviewed guidance supports at least three consecutive IUI cycles before moving to IVF, though age and diagnosis often shorten that window.

Searching for the best IUI clinic surfaces marketing pages, not the specifics that separate a well-run cycle from a mediocre one. Those specifics show up in the monitoring, the timing, and the lab work, well before you ever see a treatment room.

Markham Fertility Centre’s IUI program is built around getting each of those right.

Monitoring rigor: how closely a cycle actually gets tracked

IUI monitoring exists to answer one question: is a follicle developing on schedule, and how big is it right now. That takes repeated ultrasound and bloodwork across the 10 to 12 day stimulation window, tracking two things at each visit:

• Follicle size and count, via transvaginal ultrasound
• Hormone levels, primarily estradiol and LH, via blood testing

Follicles in the 18 to 22mm range at trigger time are generally associated with the strongest outcomes. Too small, and the egg may not be mature. Too many mature follicles at once raises the risk of a multiple pregnancy, a real clinical consideration that can determine whether a cycle proceeds or gets canceled.

Visit frequency varies by protocol, but most cycles involve two or more ultrasound visits in the days leading up to the trigger.

Timing the insemination: two ways clinics do it

Sperm needs to be in the uterus close to ovulation, and insemination is generally scheduled within 24 to 36 hours of the signal a clinic uses to predict it.[^1] Clinics work with two:

• A trigger shot: an injection of hCG that prompts ovulation on a predictable schedule, so the insemination can be booked against it
• A natural LH surge: bloodwork and ultrasound detect the body’s own hormone surge, and the insemination is timed from that

Neither method is the right one on its own. Pregnancy in an IUI cycle depends on many factors, including age, diagnosis, follicle development, and sperm quality, and the timing method is one part of that larger picture. 

What matters is that the choice fits the cycle: how predictable ovulation is, how the patient responded to medication, and what the monitoring shows.

At Markham Fertility Center, most IUI cycles use a trigger shot, with a natural LH surge used in some cases, decided on each patient’s individual situation.

How the sample gets handled in the lab

Before insemination, whether the sample comes from a partner or a donor, it goes through sperm washing: a lab process that removes seminal fluid, dead sperm, and debris, concentrating what’s left into a small, highly motile sample. Two things affect how well this works: the resulting count, and how quickly the sample gets processed.

Post-wash TMSC	What it generally means
Above 10 million	Best IUI outcomes, a small margin above the 2 to 10 million range
2 to 10 million	Standard IUI success rate, around 15%
Below 2 million	Slightly reduced success rate, around 10%

Speed matters too. Sperm sitting at room temperature or exposed to processing delays shows measurably more oxidative stress within the first hour, which can affect motility.[^2] A sample processed immediately, in-house, is handled differently than one that gets shipped out or queued behind other work.

How decisions get made across cycles

Not every IUI cycle results in pregnancy, and how that gets handled matters as much as how the first cycle ran.

Fertility and Sterility, the American Society for Reproductive Medicine’s journal, notes that three to six cycles of IUI have become standard practice, with at least three consecutive cycles generally recommended before moving to IVF.[^3] That timeline commonly compresses for a few reasons:

• Patients age 35 or older, where egg quality and quantity decline faster
• Significant male factor infertility, where per-cycle odds are already lower
• Blocked or damaged fallopian tubes, where IUI may not be a viable option at all

Why Patients Choose Markham Fertility Centre

• Physician-performed inseminations: every IUI is performed by one of the clinic’s five reproductive endocrinologists directly, not delegated to a nurse or technician
• On-site andrology lab: sperm washing and preparation happen in-clinic, roughly two hours from collection to insemination, with no shipping or third-party delay
• Follicle safety protocol: the target is one to three mature follicles; cycles are adjusted or cancelled if more than three develop, to manage multiple-pregnancy risk
• Five monitoring locations spanning Ontario, from the Greater Toronto Area to Sudbury: Markham, Barrie-Innisfil, Oshawa, Orillia, and Sudbury
• Ontario Fertility Program participant: IUI is funded with no lifetime cycle limit, within the clinic’s annual budget allocation, which renews every April
• Individualized cycle planning: the clinic generally recommends 3 to 5 IUI attempts before revisiting IVF, adjusted for age, diagnosis, and how earlier cycles went

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FAQ

What follicle size is ideal before triggering ovulation for IUI? 

Most protocols target 18 to 22mm at the time of trigger. Follicles outside this range are linked to lower success rates, often because the egg inside hasn’t fully matured, which is why repeated ultrasound monitoring throughout the stimulation phase matters more than a single check.

What’s the difference between a trigger shot and timing off a natural LH surge? 

A trigger shot is an hCG injection that prompts ovulation on a predictable schedule, so the insemination can be booked from it. Timing off a natural LH surge means bloodwork and ultrasound detect the body’s own hormone signal, and the insemination is scheduled from that. Clinics choose between them based on the individual cycle, not a fixed rule.

How many ultrasound visits should I expect during an IUI cycle? 

Most cycles involve two to three or more monitoring visits across the 10 to 12 day stimulation window, tracking follicle size by transvaginal ultrasound and hormone levels, primarily estradiol and LH, by bloodwork.

How many IUI cycles should I try before considering IVF? 

Research supports at least three consecutive cycles before making that call, with three to six cycles being common practice overall. Age and specific diagnoses can shorten that treatment window considerably.

Does it matter who performs the insemination?

 It can. Some clinics have the procedure performed by nurses or technicians rather than the treating physician. At Markham Fertility Centre, every insemination is done directly by one of the clinic’s reproductive endocrinologists, part of physician-led care for each patient.

Is IUI covered by the Ontario Fertility Program? 

Yes, with no lifetime cycle limit. Coverage is tied to each clinic’s annual funding allocation, which renews every April, so funded availability can shift depending on demand through the year.

Sources

• RESOLVE: The National Infertility Association, “Intrauterine Insemination (IUI)”  
• Fertility and Sterility (ASRM), “Should couples with unexplained infertility have three to six cycles of intrauterine insemination with ovarian stimulation or in vitro fertilization as first-line treatment?”
• PMC, “Timing Matters? Impact of Early Sperm Processing on Motile Sperm Recovery, Fertilization, Blastocyst Rate, and Pregnancy Outcomes in IUI and IVF” 

Footnotes

[^1]: RESOLVE: The National Infertility Association, “Intrauterine Insemination (IUI).” 

[^2]: PMC, “Timing Matters? Impact of Early Sperm Processing on Motile Sperm Recovery, Fertilization, Blastocyst Rate, and Pregnancy Outcomes in IUI and IVF,” PMC12653404. 

[^3]: Fertility and Sterility (ASRM journal).