Natural (unstimulated) intrauterine insemination (IUI) means you undergo the procedure without using fertility drugs to regulate or trigger ovulation (stimulated IUI). For certain fertility diagnoses, this is suitable if your menstrual cycles are regular and you have no problems with ovulation.
The Natural Insemination Cycle
A complete fertility evaluation precedes a recommendation for natural insemination. Preparation for an IUI cycle includes the following:
- You keep track of your menstrual cycle starting on day one to time the procedure.
- You test your urine with ovulation predictor (LH) sticks for a few days in the middle of your cycle or do an LH blood test to estimate your day of ovulation.
- Your IUI is scheduled between 24 to 36 hours after the day of a strongly positive LH test (the LH surge), during which ovulation occurs. The insemination is usually between days 12 to 16.
Your fertility specialist might also recommend one or two ultrasounds in your cycle to monitor when an egg is close to ovulating.
The IUI Procedure
IUI is a simple office procedure that takes just a few minutes to perform. You don't need anesthesia because you will have little or no discomfort. The insemination procedure includes these steps:
- On the day of the IUI, your partner drops off a sperm specimen to your fertility clinic.
- The sperm sample is "washed" in the lab to get rid of the semen (which causes painful uterine cramps) and other detrimental factors and to select the most normal and motile sperm.
- The prepared sperm is suspended in a small amount of insemination fluid.
- Your doctor inserts a vaginal speculum to visualize your cervix, similar to a pelvic exam for a PAP smear.
- He inserts the sperm specimen high inside your uterus through a thin, soft, flexible special IUI catheter.
- After the insemination, you might be asked to rest in the office for about 15 minutes and then can return to your normal activities.
If you are using frozen donor sperm, the specimen is thawed on the day of your IUI and prepared for insemination.
Indications for Intrauterine Insemination
You are a candidate for natural insemination instead of stimulated IUI if your menstrual cycles and ovulation are regular. In some circumstances, your doctor might suggest adding hormones if you don't get pregnant after three cycles.
Putting the sperm inside the uterus overcomes barriers that decrease the ability of sperm to get to your fallopian tubes and egg. According to an American Society for Reproductive Medicine fact sheet, these barriers include the following problems:
- Cervical factor: A tight cervix or poor mucus in the cervical canal can prevent sperm from penetrating into the uterine cavity, and IUI bypasses this problem.
- Mild male factor infertility: Mild abnormal sperm parameters, such as low volume semen and poor sperm motility can make it hard for sperm to reach the egg,
- Need for donor sperm (donor insemination): This is an option if your partner has insufficient sperm, or there are few or no normal sperm or not enough motile sperm.
- Sexual dysfunction: This includes couples who have difficulty with vaginal intercourse including those with a disability or men with erectile dysfunction.
- Unexplained infertility: When a full infertility work-up doesn't show any obvious reason for the infertility, IUI might be suggested. However, the benefit of IUI for this diagnosis compared to extended, timed intercourse to increase the chance of pregnancy has not been proven.
IUI is not suitable, however, if your tubes are closed and unable to pass the egg to the sperm. You must have open tubes and a normal uterine cavity and endometrial lining to be eligible for IUI.
Pros and Cons
The risk of complications from natural insemination is low. Other information to consider includes the following:
- Natural intrauterine insemination avoids the increased risk of multiple pregnancies from fertility drugs, such as Clomid or injectable hormones used in stimulated IUI.
- It avoids the risk of ovarian hyperstimulation from fertility drugs.
- The process is simpler than stimulated IUI and is less invasive than in vitro fertilization (IVF).
- It costs less than stimulated IUI and IVF because there are no fertility drugs used, and it avoids the cost of additional ultrasound monitoring and blood work.
- The overall success rate of IUI is lower than that of IVF.
IUI Success Rate
IUI pregnancy success rate ranges from 4 to 20 percent. Success depends on the fertility diagnosis and is similar for women under age 35 for both natural or stimulated IUI. However, pregnancy and live birth rates are greater for IVF than for IUI, as reviewed in an article by Resolve (The National Fertility Association).
In general, the success rate of IUI decreases with age for both types of procedures. A 2007 article in the Journal of Assisted Reproduction and Genetics, however, suggests natural insemination might have a better pregnancy rate compared to stimulated IUI.
Natural intrauterine insemination costs about $300 to $700 per cycle compared to $2,000 or more for stimulated IUI. Consider that you might need several cycles before you conceive. The average cost of IUI varies, and the cost of IVF is $12,000 or more per cycle.
Finding a Fertility Doctor
Your gynecologist can do your fertility evaluation but often prefers to refer you to a fertility specialist for treatment. You can ask your doctor for his preference or ask family or friends who have gone through fertility procedures. In addition, you can search online for fertility doctors or centers in your area.
Discuss Your Options
Natural intrauterine insemination is the simplest of invasive fertility procedures. However, in some situations it might be more cost-effective and you might have a better chance of conceiving if you bypass several IUI cycles and proceed to IVF. This is more important if you are older than age 35. Discuss your treatment options with your fertility specialist so you can make the best decision.