Intrauterine insemination (IUI) is a fertility treatment where concentrated sperm is placed directly into the uterus through a thin tube, timed to coincide with ovulation. The procedure itself takes only a few minutes, but the full process spans most of a menstrual cycle, from initial monitoring through insemination and the waiting period that follows.
Who IUI Works Best For
IUI is typically a first-line fertility treatment, meaning it’s one of the earlier options tried before moving to more intensive procedures like IVF. It works well for several specific situations: unexplained infertility, mild male factor infertility (such as lower sperm count or motility), and cervical factor infertility, where the cervix itself creates a barrier to sperm reaching the egg. It’s also the most common method used when donor sperm is needed.
IUI is not the right fit when fallopian tubes are blocked, since sperm still needs to meet the egg in the tube for fertilization to happen. Severe endometriosis or significant pelvic adhesions also point toward IVF, which bypasses the tubes entirely. For unexplained infertility, most providers will try three or four IUI cycles before recommending IVF.
Testing Before You Start
Before your first IUI cycle, both you and your partner will go through a workup. This usually includes a pelvic exam, blood tests for hormones and prenatal screening, infectious disease screening, and a semen analysis. Your provider will also evaluate whether your fallopian tubes are open, either with an X-ray dye test or a specialized ultrasound. Starting prenatal vitamins about three months before treatment is a good idea, since certain nutrients take time to build up.
Step 1: Ovulation Monitoring or Stimulation
Timing is everything with IUI. Sperm needs to be in the uterus within a narrow window around ovulation, so the first chunk of the cycle is devoted to tracking when your body will release an egg.
Some cycles are done without medication, relying on your natural ovulation. You’ll use an at-home urine test kit that detects a surge in luteinizing hormone, the signal that triggers your ovary to release an egg. Your provider may also use ultrasound to monitor follicle growth.
In many cases, though, fertility medications are used to improve the odds. Oral medications are taken for about five days early in your cycle to stimulate egg development. Injectable medications, which are stronger, may be used for up to two weeks. These drugs increase the chance that you ovulate and may cause more than one egg to mature, which raises success rates but also increases the chance of multiples. Your provider will monitor you with ultrasounds and sometimes blood work to check how your ovaries are responding.
Step 2: Sperm Preparation
On the day of insemination, a semen sample is collected (or a frozen donor sample is thawed) and then “washed” in a lab. This process separates the healthiest, most active sperm from the surrounding fluid, dead sperm, and other cellular debris. Raw semen can’t be placed directly into the uterus because it contains compounds that can cause severe cramping.
Labs use a few different techniques. In one common method, the sample is layered under a culture medium and the strongest sperm swim upward into it on their own. Another approach spins the sample through a density gradient, where layers of fluid separate sperm by quality. The result is a small, concentrated volume of the best available sperm, ready for insemination.
Step 3: The Insemination
The procedure itself is brief and straightforward. You’ll lie on an exam table, similar to a routine pelvic exam. Your provider inserts a speculum, then threads a thin, flexible catheter through the cervix and into the uterus. The washed sperm sample is pushed through the catheter. The whole insertion takes just a few minutes.
Most people describe the sensation as similar to a Pap smear, with mild cramping as the catheter passes through the cervix. It doesn’t require anesthesia, and you won’t need someone to drive you home. Some clinics ask you to lie down for 10 to 15 minutes afterward, though others let you get up right away.
After the Procedure
You can return to most normal activities the same day, but it’s wise to keep things low-key. Gentle walking, light yoga, and stretching are fine. Avoid heavy lifting (anything over about 10 pounds), intense workouts like running or weightlifting, and swimming for at least two days, since pool water can introduce infection risk.
Your provider may prescribe vaginal progesterone to support the uterine lining during the two-week wait before a pregnancy test. This is more common when injectable fertility drugs were used for stimulation, where research shows progesterone support leads to meaningfully higher live birth and pregnancy rates. When only oral fertility medications are used, the benefit of added progesterone is less clear. If prescribed, you’d typically start progesterone on the day of insemination or within two days, continuing for several weeks if pregnancy is confirmed.
Success Rates by Age
IUI success rates are modest per cycle but add up over multiple attempts. In a large analysis of over 4,200 insemination cycles, pregnancy rates per cycle broke down roughly like this:
- Under 25: about 20% per cycle
- 25 to 29: about 13% per cycle
- 30 to 34: about 11% per cycle
- 35 to 39: about 9% per cycle
- 40 to 41: about 9% per cycle
- 42 to 43: about 6% per cycle
- Over 43: about 3% per cycle
One notable finding: success rates for women aged 40 and 41 held steady with the 35 to 39 group for the first three cycles, suggesting that age alone isn’t a reason to skip IUI in your early 40s. Looking at cumulative rates across multiple cycles, roughly 22 to 28% of women under 40 achieved pregnancy after several attempts. The drop becomes more significant after 42.
What IUI Costs
IUI is significantly less expensive than IVF, which is one reason it’s often tried first. A cycle without medication can cost $1,000 or more, covering monitoring and the insemination itself. If oral fertility medications are added, expect roughly another $100 on top of that. Injectable medications are pricier, potentially adding $1,000 to $2,000 per cycle. Insurance coverage varies widely, so check your plan before starting. Since most people need more than one cycle, it helps to budget for at least three or four attempts.
The Two-Week Wait
After insemination, there’s nothing to do but wait. A pregnancy test is typically scheduled about two weeks later. During this time, you may experience light spotting or mild cramping, which can be caused by the procedure itself, progesterone supplements, or early implantation. None of these symptoms reliably predict whether the cycle worked. Home pregnancy tests taken too early can give false negatives because the hormone they detect hasn’t built up enough yet. Your clinic will schedule a blood test at the right time for an accurate result.
If the cycle doesn’t result in pregnancy, most providers recommend trying again the following month, often for a total of three to six cycles before reassessing your treatment plan.