Intrauterine insemination (IUI) is a mild and less invasive method of Assisted Reproduction. It is often used in couples with unexplained infertility or in cases where the probability of egg and sperm meeting needs to be increased.

There are two types:

• Symbolism: the husband's/partner's sperm is used.

• Heterologous insemination: donor sperm is used.

Homologous Insemination

For the success of the method it is important:

• The woman's fallopian tubes should be passable.

• The sperm sample must have satisfactory characteristics (number, motility, morphology).

The procedure can be performed during the natural cycle, however, mild pharmacological stimulation is often applied, aiming to develop 2–3 follicles, thus increasing the chances of conception.

Monitoring is done with:

• transvaginal ultrasound

• hematological measurements (estradiol, LH)

When ovulation is confirmed or induced, the sperm undergoes special laboratory processing and is then gently placed into the uterus with a thin, flexible catheter. Thus, the most motile sperm have an increased chance of reaching the fallopian tubes where natural fertilization occurs.

The method presents the best success rates in women up to 38 years of age.

Heterologous Insemination (with donor)

In cases where the partner's sperm sample is not available or is not usable, donor sperm from a certified sperm bank can be used.

The procedure for the woman remains exactly the same as that of homologous insemination.

On the day of ovulation:

• 1–2 ampoules of frozen sperm are thawed.

• The sample is prepared in the laboratory.

• It is placed in the uterus in the same painless way.

Advantages of IUI

• It is a simple and painless procedure.

• It does not require anesthesia.

• It can be done in a natural or slightly stimulated cycle.

• It is often the first therapeutic step before in vitro fertilization.

• See also: Sperm Donation & Legal Framework