How the IUI Process Works
A single IUI cycle typically follows these four stages:
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Ovarian Stimulation (Optional): You may take oral medications (like Clomid or Letrozole) or injections to encourage your ovaries to mature 1–3 eggs.
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Monitoring & Triggering: Doctors use ultrasounds and blood tests to track follicle growth. Once the eggs are ready, a “trigger shot” (hCG) is given to induce ovulation.
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Sperm Preparation: On the day of the procedure, a semen sample is “washed” in a lab. This removes chemicals that cause cramping and concentrates the most active, healthy sperm into a tiny amount of fluid.
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The Insemination: A thin, flexible catheter is inserted through the cervix into the uterus to inject the sperm. It takes about 5–10 minutes and feels similar to a Pap smear.
Intrauterine Insemination (IUI), often called “artificial insemination,” is a fertility treatment that involves placing concentrated, washed sperm directly into a woman’s uterus.
While IVF happens in a lab, IUI happens inside the body. The goal is to give the sperm a “head start” by bypassing the cervix and placing them closer to the egg at the exact time of ovulation.
How the IUI Process Works
A single IUI cycle typically follows these four stages:
-
Ovarian Stimulation (Optional): You may take oral medications (like Clomid or Letrozole) or injections to encourage your ovaries to mature 1–3 eggs.
-
Monitoring & Triggering: Doctors use ultrasounds and blood tests to track follicle growth. Once the eggs are ready, a “trigger shot” (hCG) is given to induce ovulation.
-
Sperm Preparation: On the day of the procedure, a semen sample is “washed” in a lab. This removes chemicals that cause cramping and concentrates the most active, healthy sperm into a tiny amount of fluid.
-
The Insemination: A thin, flexible catheter is inserted through the cervix into the uterus to inject the sperm. It takes about 5–10 minutes and feels similar to a Pap smear.
Success Rates (2025 Benchmarks)
IUI success depends heavily on age and the underlying cause of infertility. Unlike IVF, where success is higher per try, IUI is often about cumulative success over 3–6 cycles.
| Age Group | Success Rate (Per Cycle) | 3-Cycle Cumulative Success |
| Under 35 | 15% – 20% | ~40% – 50% |
| 35 – 37 | 10% – 15% | ~30% – 35% |
| 38 – 40 | 8% – 10% | ~20% – 25% |
| Over 40 | 2% – 5% | < 10% |
IUI vs. IVF: Key Differences
| Feature | IUI | IVF |
| Where fertilization happens | Inside the body (fallopian tubes) | Outside the body (lab dish) |
| Complexity | Simple office procedure | Minor surgery (egg retrieval) |
| Primary Risk | Multiple pregnancy (twins/triplets) | OHSS (ovarian overstimulation) |
Common Side Effects
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Physical: Mild cramping, light spotting for 1–2 days, and bloating (if using fertility drugs).
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Emotional: The “Two-Week Wait” (TWW) can be stressful as you wait to take a pregnancy test.
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Multiple Births: Because IUI often involves stimulating multiple eggs, there is a 5% to 15% chance of twins if medications are used.
Who is IUI Best For?
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Couples with unexplained infertility.
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Men with mild sperm count or motility issues.
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Women with cervical mucus problems or scarring.
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Single women or same-sex couples using donor sperm.