Intrauterine insemination involves the introduction of “washed sperms” into the woman’s womb. It is usually performed for couples with unexplained or mild male factor infertility, mild or minimal pelvic endometriosis and cervical factor infertility. The prerequisites are at least one patent fallopian tube and a total exceeding one million, preferably more than five million progressive motile sperms after “washing”.
IUI can be performed in a natural or stimulated cycle. Natural cycle IUI is indicated in couples with sexual dysfunction or cervical factor infertility and has been shown to be of no benefit (compared with natural sexual intercourse) in other causes of infertility (vide supra). Multi-follicular development can be induced with oral drugs or daily injections; in either case, the female partner is closely monitored as to the number of developing eggs and their growth rate. When not more than three eggs (follicles) have reached mature size, ovulation will be triggered so that it will take place 36 to 40 hours later. On the day of ovulation, a semen sample is collected two hours prior to the procedure. If the male partner were out of town or otherwise occupied, a sample could be cryopreserved in advance and thawed on the day of ovulation. The semen sample (fresh or frozen-thawed) is processed, commonly known as “sperm washing”. During this process, it is subjected to a series of steps whereby the progressive motile sperms are separated from the non-motile and non-progressive motile sperms, the latter faction together with the seminal fluid and other impurities are removed and discarded. The sperms with high motility are then concentrated in a small volume (0.4-0.6 mL) of culture medium and the sample is ready for use.
The IUI procedure takes a few minutes and is similar to taking a routine Pap smear. It is indicated in couples with unexplained infertility, couples where the men has low sperm count (oligozoospermia) or reduced motility (asthenozoospermia), mild pelvic endometriosis, hostile cervical mucus, retrograde ejaculation and other sexual dysfunction.