This therapeutic modality is also commonly called artificial insemination. For many couples, intrauterine insemination(IUI) is a more affordable and less invasive therapeutic alternative to in vitro fertilization (IVF). This procedure is usually performed when there are problems with sperm (low count or low motility), an incompatibility between the sperm and the cervical mucus, endometriosis or simply for unexplained infertility. It can also be performed to overcome conditions associated with a man’s inability to ejaculate inside of a woman’s vagina due to impotence, premature ejaculation or other medical conditions. An insemination could also be performed in women incapable of tolerating normal sexual intercourse, as in cases of vaginismus.
In contrast to in-vitro fertilization, in which embryos are placed in the uterus, intrauterine insemination (IUI) places motile sperm inside of the endometrial cavity. IUI could be performed in either a natural cycle or along with an ovulation induction cycle (using clomiphene citrate, letrozole or injectable gonadotropins). Couple who are experiencing infertility may use IUI as a means to increase the likelihood of pregnancy by improving the delivery of sperm to the egg, at the time of ovulation.
IUI is an easy office procedure that utilizes a specially prepared sperm sample from the male partner or a sperm donor. A sperm donor could be used if the male partner has no sperm or poor quality sperm (low motility or low normal morphology), previous chemotherapy or radiation therapy for malignant diseases or genetic disorders that may be inherited by a child. It is recommended that the male partner abstain from any ejaculation (masturbation/sexual intercourse) for 3-4 days prior to the insemination day.
The male partner will provide a semen sample between 1-2 hours before the insemination takes place. The sperm will be washed, a procedure in which the sperm are separated from the seminal/prostatic fluid. The sperm washing allow the concentration of the most motile sperm. Studies have indicated that sperm washing also allows the sperm to undergo a process called capacitation, in which the sperm achieve a faster motility state. The increased motility allows the sperm to penetrate the egg shell, called the zona pellucida, more readily. Thus, the IUI procedure increases the probability of fertilization of an egg.
During the insemination procedure, the processed sperm sample is carefully injected into the uterus by means of a fine plastic catheter, around the time of impending ovulation. The procedure only takes a few minutes; is relatively painless and well tolerated by most patients. The patient is able to resume their usual activities immediately following the IUI procedure. If a pregnancy does not result from the initial IUI, the procedure may be repeated during the following menstrual cycles. Usually the IUI procedure is not recommended for more than 3 times. If a patient does not achieve a pregnancy by the third IUI attempt, in which adequate ovulation has been documented, a fertilization problem may be present. Therefore, a fertilization failure is best treated by means of an in vitro fertilization cycle using intracytoplasmic sperm injection (ICSI).
Even though IUI allows the placement of sperm closer to the fallopian tubes, the process is less effective than in vitro fertilization in achieving a pregnancy. In order for a patient to undergo an IUI treatment, the fallopian tubes must be open (patent). Therefore, IUI is not effective in couples experiencing infertility associated with blocked or damaged fallopian tubes/vas deferens, as in cases where a patient has undergone either a tubal ligation or a vasectomy procedure. For these cases of tubal factor infertility, in vitro fertilization is the treatment of choice.