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IUI (Intrauterine Insemination)

IUI, or intrauterine insemination, is one of the most commonly performed reproductive procedures in the world. IUI has been used in one form or another for almost 200 years. IUI today involves inserting washed, concentrated sperm directly through the cervix into the uterus. “Unwashed” sperm must never be placed in the uterus, as serious and sometimes even fatal allergic reactions can occur.

IUI is useful when there are infertility issues related to a cervix that is scarred and closed, when there are low numbers of sperm, or even if the cause of infertility is unknown. Cervical mucus must be of the correct consistency for the sperm to swim to the site of fertilization. Active infection of the cervix may impair sperm motility, so should be treated. If cervical mucus is absent or the cervix is scarred due to past cervical surgery, sperm may be unable to pass through the cervix normally.

IUI is sometimes a first-line treatment for unexplained infertility. IUI is often performed in stimulated cycles, meaning Clomid or FSH is given to stimulate follicular development, thus increasing the chances of a successful IUI. When women undergo ovulation induction with FSH, they must come to our office for repeat ultrasound monitoring and estradiol measurements. These tests ensure that the follicles are properly developing and lower the chances of adverse drug reactions such as ovarian hyperstimulation syndrome.

IUI ideally be performed by a trained infertility specialist/reproductive endocrinologist. Infertility specialists undergo years of advanced training in FSH administration and the management of difficult IUI cycles. They have access to laboratories that process sperm optimally, and can also do swim up procedures of semen to improve the IUI specimen. One IUI risk is that it increases the chance of multiple births because the number of eggs ovulated can be difficult to control.

This is unlike IVF, where a set number of embryos are transferred to the uterus. Most of the high order (>4) births reported in the media are the result of IUI cycles that were administered by a non-specialist in combination with injectable FSH. Specialists are trained to limit the chances of this unwanted potential side effect of IUI.

Three IUI cycles will usually be tried, depending upon the couple's history, after which IVF may be the next choice. In some cases of infertility due to issues such as tubal disease, advanced female age, and male factor, IVF is the first-line treatment and IUI is not attempted.

Read the IUI policy on using donor sperm.