Intrauterine insemination (IUI), is the process of placing sperm into a woman’s uterus at the time that an egg is released from the ovary (ovulation). Sperm used during the IUI procedure are typically “washed” and can either be obtained from the woman’s male partner or from a sperm donor. “Washed” sperm — or sperm that is separated from the fluid that it swims in (seminal fluid) — makes the sperm more mobile and increases the number of moving sperm within the reproductive tract. The greater the number of moving sperm means the greater the likelihood that sperm will locate an egg.
To place the sperm inside the uterus, a speculum is gently inserted into the vagina and a very thin catheter is passed through the cervix into the uterus. This procedure causes no more discomfort than is usually experienced during a pap smear. The washed sperm is then released from the catheter. The IUI process, however, does not guarantee that the egg and sperm will come together to form an embryo (fertilization). The sperm must reach and fertilize the egg on its own.
IUI is used for a variety of conditions, including male infertility, cervical or mucous problems and to more exactly time the interaction of the sperm with the ovulating egg. For many patients and couples undergoing IUI, the use of hormone medications is needed and/or recommended to concurrently enhance the female partner’s fertility.
It is important to understand the difference between IUI and IVF (In Vitro Fertilization). With IUI, fertilization happens inside the body. The procedure just helps get the healthiest, most robust sperm as close to the egg as possible. If fertilization does occur, the embryo travels down the fallopian tube and hopefully implants in the uterus. With IVF, fertilization occurs outside the body in the IVF laboratory. The fertilized egg (now an embryo) develops for the next few days, then is transferred into the uterus for hopeful implantation.