What Is Intrauterine Insemination (IUI)?
Intrauterine insemination (IUI) is a fertility treatment that places specially washed sperm directly into the uterus around the time of ovulation. It is often the first line of treatment for couples with unexplained infertility, mild male factor issues, or cervical mucus problems. Compared to IVF, IUI is less invasive and more affordable, but success depends on careful timing and a healthy reproductive system. This guide walks you through the IUI procedure step by step, from preparation to recovery.
Step 1: Initial Consultation and Testing
Before starting IUI, both partners undergo a fertility evaluation. For women, this includes ovarian reserve testing (AMH, FSH, antral follicle count) and a hysterosalpingogram (HSG) to confirm at least one open fallopian tube. For men, a semen analysis checks sperm count, motility, and morphology. If sperm parameters are severely low, IUI may not be recommended, and doctors might suggest IVF or ICSI instead.
Step 2: Ovarian Stimulation (Optional but Common)
In a natural cycle, IUI is timed to ovulation without medication. However, many clinics prescribe oral fertility drugs (clomiphene or letrozole) or low-dose gonadotropins (injections) to stimulate the ovaries to produce one or two mature eggs. This increases the chance of conception but also raises the risk of multiple pregnancy. Ultrasound monitoring and blood tests track follicle growth and hormone levels (estrogen and LH) every few days.
Step 3: Trigger Shot and Timing
When a dominant follicle reaches 18–20 mm in diameter, a trigger shot of human chorionic gonadotropin (hCG) is given to induce final egg maturation and ovulation. Ovulation occurs approximately 36 hours after the injection. The IUI procedure is scheduled 24–36 hours after the trigger, so that sperm are present in the fallopian tubes when the egg is released. If using a natural cycle, ovulation predictor kits (OPKs) or blood LH tests determine the timing.
Step 4: Semen Collection and Sperm Washing
On the day of IUI, the male partner provides a semen sample (usually by masturbation) after 2–5 days of abstinence. The sample is processed in the lab using a technique called sperm washing, which separates healthy, motile sperm from seminal fluid, debris, and non-motile sperm. This concentrated sperm sample (0.3–0.5 mL) is placed in a sterile catheter for insemination. Sperm washing also reduces the risk of uterine cramping and infection.
Step 5: The IUI Procedure
The IUI procedure itself takes only 5–10 minutes and is performed in a doctor’s office. You lie on an exam table with your feet in stirrups. A speculum is inserted into the vagina to visualize the cervix. The doctor passes a thin, flexible catheter through the cervix into the uterus and gently injects the washed sperm. Most women feel mild discomfort similar to a Pap smear. After the procedure, you may rest for 10–15 minutes before resuming normal activities. There is no need for bed rest, but some clinics recommend lying down for 20 minutes to maximize sperm retention.
Step 6: Luteal Phase Support
After IUI, the luteal phase (the time between ovulation and expected period) is supported with progesterone supplements, usually as vaginal suppositories or oral pills. Progesterone helps thicken the uterine lining and maintain an early pregnancy. Many fertility specialists prescribe progesterone for 14 days until a pregnancy test is performed. For more details on progesterone types and timing, see our article on luteal phase support in IVF (similar principles apply to IUI).
Step 7: Pregnancy Test and Follow-Up
About 14 days after IUI, a blood test (beta-hCG) is done to check for pregnancy. If positive, an ultrasound is scheduled at 6–7 weeks to confirm a viable intrauterine pregnancy. If negative, the cycle is considered unsuccessful, and you can discuss next steps with your doctor. Many couples try 3–6 cycles of IUI before moving on to IVF, especially if the woman is under 35 and has no tubal issues.
What to Expect After IUI: Side Effects and Recovery
Most women experience no significant side effects. Some report mild cramping or spotting immediately after the procedure, which resolves within a day. Ovarian hyperstimulation syndrome (OHSS) is rare with oral medications but possible with injectable gonadotropins. Symptoms include bloating, nausea, and abdominal pain—contact your doctor if severe. Lifestyle factors like stress management, moderate exercise, and adequate sleep can support fertility. Learn more in our guide on fertility lifestyle habits for IVF success, which also applies to IUI cycles.
Success Rates and Factors That Influence Outcome
IUI success rates vary by age, cause of infertility, and number of cycles. According to the American Society for Reproductive Medicine, live birth rates per cycle range from 5–15% for women under 35 to 2–5% for women over 40. Factors that improve success include: using fertility drugs, having at least one patent fallopian tube, normal sperm parameters, and good timing. Mayo Clinic notes that IUI is most effective when combined with ovarian stimulation and careful monitoring.
When to Consider Alternatives to IUI
If IUI fails after several cycles, or if there is severe male factor infertility, bilateral tubal blockage, or advanced maternal age, your doctor may recommend IVF. Our detailed comparison of IUI vs IVF can help you weigh the options. For single women or same-sex couples, IUI with donor sperm is also a viable path—see fertility treatment options for single women.
Conclusion
Understanding the IUI procedure step by step helps reduce anxiety and sets realistic expectations. From initial testing to the quick insemination process and two-week wait, each stage is designed to maximize the chance of pregnancy while minimizing risk. If you’re considering IUI, consult a fertility specialist to determine if it’s the right first step for you. Always remember that fertility treatments require patience and support—both medical and emotional.
Disclaimer: This article is for informational purposes only and does not replace professional medical advice. Always consult a qualified healthcare provider for personalized guidance.