Preparation and Timing of Insemination
Putting sperm directly into the uterus, instead of the vagina or cervix, is a type of artificial insemination called intrauterine insemination (IUI). Coordinating the woman's menstrual cycle with the IUI is critical for fertilization. One or more eggs are ovulated or released from the ovaries every month in a natural cycle. The ovulated egg travels into the fallopian tube where, if the timing is right, sperm and egg come together for fertilization.
The IUI is timed to occur within a few hours of the rise in circulating LH hormone that occurs with ovulation in a natural cycle. The insemination can also be coordinated in a medically-stimulated cycle by taking medication to stimulate the ovaries to produce mature eggs and then getting a hormone injection to trigger ovulation. The IUI is performed 36 hours after the trigger shot in a stimulated cycle.
Preparation of Sperm
On the day of insemination, the woman's partner produces a semen sample. Sometimes, a frozen donor sample is used. The semen is processed or "washed" by adding a wash fluid to the semen and spinning the sample in a centrifuge to remove either seminal fluids or freezing medium, if a frozen donor is used. Sometimes the semen is processed over a thick solution or gradient that holds back debris and poor quality sperm, letting the best sperm concentrate at the bottom of the test tube.
The processed sperm sample is concentrated to a minimal volume, usually less than a teaspoon. The concentrated washed semen sample is drawn up into a sterile plastic tube attached to a small syringe, called the insemination catheter.
Usually, before the insemination occurs, the nurse or physician verifies the semen information with the patient to confirm that the correct semen sample is used.
Intrauterine Insemination
An intrauterine insemination is like a pelvic exam in that a speculum is inserted into the vagina to get a better view of the cervix, the opening into the uterus. The catheter containing sperm is carefully inserted through the cervical opening until the tip of the catheter extends into the uterus. Once the catheter is placed correctly, the syringe is pushed to expel the fluid containing sperm directly into the uterus. Sometimes a patient is asked to recline for an hour or less.
Two weeks later, the patient takes a urine or blood pregnancy to test to determine if the intrauterine insemination resulted in conception.
