Intrauterine Insemination (IUI)
IUI places washed sperm directly into the uterus at the time of ovulation — a simpler, less expensive first step before IVF with 10–20% success rates per cycle. This guide covers who benefits most, what to expect, and when to move on.
What Is IUI?
Intrauterine insemination is one of the most common fertility treatments in the world. Unlike natural conception (where sperm must travel from the vagina through the cervix into the uterus) or home ICI insemination (which deposits sperm near the cervix), IUI bypasses the cervix entirely — placing sperm directly into the uterine cavity, much closer to where fertilization occurs.
Sperm is first "washed" — a lab process that removes seminal fluid, dead sperm, and debris, concentrating motile sperm in a small volume. This process also reduces the risk of uterine cramping or infection that would occur if raw semen were placed directly in the uterus.
IUI is less invasive and far less expensive than IVF, making it a common first-line treatment for couples and individuals who don't have diagnoses that require IVF from the outset. For the right patient, IUI offers a meaningful chance of pregnancy at a fraction of the cost.
The IUI Process — Step by Step
Most IUI cycles are completed within 2 weeks from cycle start to insemination day.
Baseline Evaluation
Before starting IUI, your doctor will confirm open fallopian tubes (via HSG), evaluate your partner's semen analysis, and assess your ovarian reserve. These findings determine whether IUI is appropriate and which protocol to use.
Ovulation Induction (Optional)
In a stimulated IUI cycle, oral medications (letrozole or Clomid) or low-dose injectable gonadotropins are used to develop 1–2 mature follicles. This improves timing precision and slightly increases the number of eggs available for fertilization.
Monitoring
One or two transvaginal ultrasounds track follicle growth. When the lead follicle reaches 17–20mm, a trigger injection (hCG or Lupron) is given to induce ovulation within 36–40 hours.
Sperm Preparation
On the day of the procedure, a semen sample is provided (or frozen/donor sperm is thawed) and processed by the embryology lab. Sperm washing removes seminal fluid, dead sperm, and debris — concentrating motile sperm in a small volume of media.
The Insemination
A speculum is placed and a soft catheter is passed through the cervix into the uterine cavity. The concentrated sperm suspension (0.3–0.5mL) is gently injected. The procedure takes approximately 5 minutes. Mild cramping is common; most patients rest for 10–15 minutes.
Two-Week Wait & Pregnancy Test
A blood beta-hCG test is performed 14 days after IUI to confirm pregnancy. A positive result triggers a follow-up ultrasound at 6–7 weeks. If unsuccessful, you and your doctor will discuss whether to repeat IUI or escalate to IVF.
IUI Success Rates
Success rates vary significantly by age and diagnosis. These are live birth rates for stimulated IUI cycles.
By Age Group
| Age | Per Cycle | After 3 Cycles | Guidance |
|---|---|---|---|
| Under 35 | 12–20% | 35–50% | Best outcomes; try up to 4–6 cycles |
| 35–37 | 10–15% | 28–40% | Consider earlier IVF escalation |
| 38–40 | 6–10% | 15–25% | Escalate to IVF after 2–3 cycles |
| 41+ | 2–5% | 5–12% | IVF usually recommended first-line |
By Diagnosis — Who Benefits Most
How Much Does IUI Cost?
IUI is significantly less expensive than IVF per cycle — though costs add up across multiple cycles.
When to Skip IUI and Go Directly to IVF
Find an IUI Clinic Near You
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