In an IUI procedure, the practitioner inserts specially treated sperm through the cervix into the woman’s uterus. IUI increases the likelihood of fertilization. This procedure is performed around the time of ovulation. In some cases, particularly if low sperm count is a concern, two IUI procedures can be performed several hours apart. IUI may use the partner’s sperm, or if indicated, sperm from a donor.

Intrauterine insemination with partner’s sperm can be used as a potentially effective treatment for infertility of all causes in women under about age 45 except for cases with tubal blockage, severe tubal damage, very poor egg quantity and quality, ovarian failure (menopause), and severe male factor infertility. In vitro fertilization with the woman’s eggs or IVF with donor eggs are alternatives for couples that are not candidates for artificial insemination.

It is most commonly used for infertility associated with endometriosis, unexplained infertility, anovulatory infertility, very mild degrees of male factor infertility, cervical infertility and for some couples with immunological abnormalities.

It is a reasonable initial treatment that should be utilized for a maximum of about 3-6 months in women who are ovulating (releasing eggs) on their own. It can be reasonable to use it for somewhat longer than this in women with anovulation that has been stimulated to ovulate.

It should not be used in women with blocked fallopian tubes. Tubal patency should be demonstrated prior to performing insemination. This is usually done with an x-ray study called a hysterosalpingogram.

It has very little chance of working in women that are over 40 years old, or in younger women with a significantly elevated day 3 FSH level, or other indications of significantly reduced ovarian reserve.

If the sperm count, motility or morphology is slightly low, insemination is quite unlikely to be successful. In that situation, IVF with ICSI is indicated and has high success rates.

How is insemination performed?

• The woman usually is stimulated with medication to stimulate multiple egg development and the insemination is timed to coincide with ovulation.
• A semen specimen is either produced at home or in the office by masturbation after 2-5 days of abstinence from ejaculation.
• The semen is “washed” in the laboratory (called sperm processing or sperm washing). By this process, the sperm is separated from the other components of the semen and concentrated in a small volume. Various media and techniques can be used to perform the washing and separation, depending on the specifics of the individual case and preferences of the laboratory. The sperm processing takes about 20-60 minutes, depending on the technique utilized.
• The separated and washed specimen consisting of a purified fraction of highly motile sperm is placed either in the cervix or high in the uterine cavity using a very thin, soft catheter.

Most programs have the woman remain lying down for 5 minutes following the procedure, although this has not been shown to improve pregnancy rates. Since the sperm is above the level of the vagina, it will not leak out when she stands up.

This procedure, if done properly, usually seems similar to a pap smear for the woman. There should be little or no discomfort.

Pregnancy rates

Success rates for intrauterine insemination vary considerably and depend on the age of the woman, type of ovarian stimulation (if any) used, duration of infertility, cause of infertility, number and quality of motile sperm in the washed specimen, and other factors. Rates for women over 35 drop off, and for women over 40 are much lower. For this reason, we are more aggressive in “older” women.

Pregnancy rates are lower when insemination is used:

• in women over 40
• in women with poor with poor quality sperm in women with moderate or severe endometriosis
• in women with any degree of tubal damage or pelvic scar tissue
• in couples with a long duration of infertility (over 3 years)p

The rates are slightly higher for women that do not ovulate on their own (anovulation) that are stimulated to ovulate with medication and then inseminated. This is because it is likely that the sole cause of their infertility is their ovulation disorder – which is overcome with the use of the ovulation stimulating medicine.

For a couple with unexplained infertility, the female age 35, trying for 2 years, and normal sperm – we would generally expect about:

• 5% chance per month of conceiving and delivering with clomiphene and intrauterine insemination for up to about 3 cycles (lower after 3 attempts)

• 8% chance per month of conceiving and delivering with injectable FSH (e.g. Follistim, or Pergonal) and insemination for up to about 3 cycles (lower after 3 attempts) 

• 50% chance of conceiving and delivering with one cycle (month) of IVF treatment (at our center – pregnancy rates vary greatly between IVF clinics)

Our IVF pregnancy and delivery rates

Ovarian stimulation with clomiphene citrate versus stimulation with injectable gonadotropins (Pergonal or Follistim)

Although there is not universal agreement in published studies or among infertility experts, intrauterine insemination with partner’s sperm in conjunction with ovarian stimulation seems to provide higher pregnancy rates than insemination in natural menstrual cycles (without ovarian stimulation).

Insemination combined with ovarian stimulation with injectable gonadotropins provides better pregnancy rates (and higher multiple pregnancy rates) as compared to insemination combined with clomiphene. Injectable gonadotropins usually stimulate more mature eggs to develop than does clomiphene. More mature follicles and eggs lead to more chance for a pregnancy. However, more follicles and eggs also entail more risk for multiple pregnancy. It is a double-edged sword…

How many insemination cycles should be done?

Most pregnancies with insemination using partner’s sperm occur in the first 3-4 attempts. The chances for success per month drop off after about 3 attempts and considerably more after about 4-6 unsuccessful attempts. Therefore, this therapy is not usually recommended for more than a maximum of 4-6 cycles. If the reason for infertility is lack of ovulation (anovulation) then it may be more reasonable to try several more cycles (6-12 cycles total). In vitro fertilization is the next step in treatment after inseminations – and has a much higher success rate per cycle.