Intrauterine insemination (IUI)
The intrauterine insemination (IUI) procedure involves direct placing of prepared donor sperm in the cavity of the womb. Intrauterine insemination has higher success rates than intracervical insemination (ICI) because it places good motile sperm near the tubes, and if it is combined with ovarian stimulation, then there is usually more than an egg is available for insemination and fertilization. Intrauterine insemination (IUI) is more expensive and requires more visits to the infertility clinic than intracervical insemination (ICI).
Insemination can be performed either in a natural cycle or a stimulated cycle (to stimulate the ovaries to produce a few follicles). There is some evidence that IUI with ovarian stimulation result in a higher pregnancy and live birth rates compared to IUI alone. It is usual for the doctor to discuss with you the pros and cons of ovarian stimulation.
Monitoring of the intrauterine insemination (IUI) treatment cycle
This is essential for stimulated cycles to see whether an excessive number of follicles develop, indicating the possibility of ovarian hyperstimulation syndrome (OHHS) or high orders multiple pregnancies (e.g. triplets and more). Monitoring is performed by ultrasound scans and blood tests. If more than four follicles develop. You doctor may advise either to withhold hCG injection and abandon your treatment cycle or to convert it to in-vitro fertilization (IVF) or gamete intra-Fallopian transfer (GIFT).
Timing of intrauterine insemination (IUI)
The precise timing of insemination is important. There are several methods for timing ovulation in natural cycles. These include measurements of basal body temperature (least accurate method), assessment of cervical mucus (not reliable), and detection of LH surge in the blood or urine and ultrasound scan. Most infertility clinics time insemination by ultrasound scans and detection of LH surge, as these are the most accurate methods. Insemination is performed at 24 and 48 hours after the urine LH surge. For stimulated cycles. hCG injection is usually given when the leading follicle is about 18 mm in diameter and the endometrium (lining of the womb) is thickened enough. Insemination is usually performed about 40 hours later.
Sperm preparation
The frozen sperm is thawed. Only washed and prepared sperm is used for IUI because neat sperm may cause severe uterine contractions, pain and sometimes collapse. The aims of washing and preparation of sperm are to separate sperm from seminal plasma; removing bacteria and other chemicals that may cause infection and irritation. It also improves sperm capacitation (this increases the sperm ability to fertilize the eggs). Sperm can be extracted from seminal plasma by a number of different methods. 'Swim up' techniques and density gradients are most commonly used. The swim up technique separates the good motile sperm by allowing them to 'swim up' into a layer of sterile culture medium. Following which they are centrifuged and re-suspended in a clean sterile culture medium (sperm wash). Density gradient separates normal live sperm from seminal plasma and other cells and debris by centrifugation on a layer of fluid containing particles that act as a filter. The normal sperm become concentrated at the bottom of the layer and can then be removed and 'washed' by centrifugation and re-suspended in clean medium.
Insemination
This is a relatively simple procedure, usually painless. The woman lies on the examination table. Your doctor will then insert a speculum into the vagina to visualize the cervix; the cervix is then cleaned with a little of sterile culture medium. The washed sperm is injected into the cavity using a fine plastic catheter.
After insemination, the patient may be asked to rest for a short period of time. Custers and colleagues from Holland (BMJ 2009) reported that women who remain rested for 15 minutes after intrauterine insemination are significantly more likely to become pregnant than women who mobilize immediately. Sexual intercourse can continue as normal during the treatment cycle.
Pregnancy testing
Pregnancy testing is performed about two weeks after insemination. In the happy event that the pregnancy test is positive, an ultrasound scan is arranged 2-3 weeks later.