Intrauterine insemination (IUI) is a form of artificial insemination intended to help women who are having difficulty conceiving. Difficulty conceiving in this case may be defined as having a partner with low sperm motility, having a hostile cervix environment, or other conditions that may make chances of getting pregnant the 'usual way' a little more difficult. Another reason people may choose IUI is if they are using donor sperm to achieve pregnancy.

IUI procedure is considered minimally invasive and low risk, and many women may choose this as a first option fertility treatment when pregnancy is not occurring after a few months to years of trying to achieve it. Unlike in vitro fertilization, it is far less expensive, costing roughly $300-1000 US Dollars (USD) per attempt. Other costs may be involved since doctors see higher pregnancy success when women also take fertility medication that stimulates the release of more than one egg at ovulation.

The basic procedure is not that different from a standard yearly gynecological exam. In a doctor's office, washed and prepared sperm is inserted well into the uterus, instead of just near or in the cervix. Placing the sperm higher up allows for greater chance that sperm will reach an egg and increases chance of pregnancy. When a woman does not have other issues that might impair pregnancy like uterine scarring from endometriosis, success of the procedure is approximately 10-20%, but this statistic requires some explanation.

Age of the woman undergoing IUI influences how likely the procedure is to be successful. Generally success of the procedure tends to decline as women near their 40s and is not considered a helpful method in most women 40 or older. IUI may not work any better than natural conception if the reason for infertility cannot be explained.

Also, the statistic above does not refer to trying once, but trying IUI usually three to six times. A single attempt in a woman under 40, without significant fertility issues, and with sperm that is very high in count has about a 7% chance of conception when fertility drugs are not used.

This form of insemination seems most effective when either injected or oral fertility drugs are used. Injected fertility drugs may boost treatment success rate to 12%, and oral fertility drugs like clomid increase success rate to 9%, per single try. One consideration when using fertility drugs is the risk of having twins or higher. When intrauterine insemination is used on its own, this risk doesn't increase.

However, if the ovaries are stimulated through fertility drugs, to produce multiple eggs, chances of having a multiple birth does go up and ranges from 5-20% depending upon which types of fertility medications you do take. Medications like Clomid tend to elevate chances of twins by 5-12%. Medications like FSH (female-stimulating hormone) increase this chance to about 20%, if the IUI procedure works.