The advantage of intrauterine over other types of insemination is that a much higher concentration of sperm enters the upper female reproductive tract thus increasing the probability that one will bind to and fertilize an egg. In fact, pregnancy rates are higher with IUI than either cervical or vaginal insemination. For this reason, cervical and vaginal inseminations are performed rarely now. IUI is the preferred method for all indications. These indications include poor cervical mucus, cervical deformities, sexual dysfunction, low sperm motility, retrograde ejaculation, therapeutic donor insemination and unexplained infertility when used in conjunction with ovulation stimulating drugs.
The technique of insemination is quite simple but determining the proper timing of the insemination can be more complex. Timing is a key factor for success with insemination. The egg is capable of being fertilized for only about 12-24 hours after ovulation. Thus, it is important that sperm be present in the fallopian tubes during this critical time. After intercourse, sperm remain viable in the female reproductive tract for at least 3 days and perhaps as long as 6-7 days so precise timing of intercourse is unnecessary. The processing of sperm for IUI, however, reduces the amount of time that they remain viable so sperm may not be present for as long after IUI. This makes the accurate timing of artificial insemination more critical.
Several techniques are available to time inseminations. A low tech but relatively effective method is to use an over the counter ovulation predictor kit (OPK). These kits provide 12-24 hours advance notice of ovulation. However, interpretation of the kits can be difficult at times thus reducing its reliability. Another method involves careful monitoring of blood hormone levels and follicle size by ultrasound to identify when the follicle approaches maturity. By administering hCG (a hormone similar to LH) we can trigger the egg’s release so that we can schedule the insemination within a few hours of anticipated ovulation.
On the day of insemination, our andrology technician begins the preparation of the semen sample about 1 hour before the scheduled insemination. If a frozen sample is to be used, either donor or partner, the specimen is removed from storage and thawed. If a fresh sample is to be used, the man collects a sample in our private collection room. On arrival in the laboratory, a brief semen analysis is performed. The technician then “washes” the sperm free from the seminal plasma which contains prostatglandin, a hormone that is very irritating to the woman’s uterus. The washed sperm are analyzed once again for count and motility before proceeding with insemination. For the insemination, we simply insert a vaginal speculum, wipe the cervix clear of mucus and insert a small catheter into the uterine canal. We instill the sperm slowly and remove the catheter. This procedure is normally painless though some women experience brief mild cramping. We have the woman remain lying down for about 15 minutes then she may go about her normal activities. We tend to discourage marathon running or bungee jumping immediately after an insemination, but otherwise, normal activity will not affect the outcome of the insemination.
The success rate from insemination depends on the clinical circumstances. A young healthy women using donor sperm because her partner has none or because she is single enjoys a very high success rate. In cases where the semen quality is very poor or the woman is in her 40’s, a lower success rate is anticipated. Please consult with your physician for an assessment of your individual prognosis.
Contolled Ovarian Hyperstimulation (COH)
“ Controlled ovarian hyperstimulation” (COH) is the term used when we administer ovulation inducing medications to women who may or may not ovulate on their own. The purpose here is to obtain multiple egg release. COH/IUI refers to the combination of COH and intrauterine insemination. By increasing both the number of eggs and the number of sperm available, we hope to improve the probability that at least one viable pregnancy will result. COH/IUI is a commonly utilized infertility treatment because it can be useful in a variety of circumstances. But, since we still depend on the tubes to transport the egg and the uterus to promote implantation, this technique is best used in patients with a normal uterine cavity and normal fallopian tubes. Since this treatment is less expensive and more likely to be covered by insurance, we often try COH/IUI before moving to IVF.
Importantly, the combination of COH and IUI are more successful than either COH or IUI alone. Consequently, when we consider using one of these treatments, we usually consider using the combination. For this treatment to be effective, we try to produce 3-4 mature follicles through COH. Too many follicles increases the risk of multiple pregnancy while too few lowers the likelihood of success. Careful monitoring of the stimulation produces the greatest success. While clomiphene can be used, the highest success rates come from gonadotropin COH. Even with a fairly good prognosis for success, not all patients will conceive promptly. We recommend at least 3 cycles but no more than 6 before moving on to other treatment options.
