Artificial insemination is a simple technique consisting of artificially depositing semen in the female reproductive tract. It is most often performed in the uterine cavity. As such, an attempt is made to shorten the distance between the ovum (egg) and the spermatozoid, enabling the two to meet.
For the artificial insemination to be successful, it is essential that at least one of the Fallopian tubes is permeable. In addition, the semen from the man must meet the minimum semen parameters (in IVI centres
, the concentration of motile (mobile) sperm after laboratory preparation must be over 3 million).
The artificial insemination treatment consists of three phases:
- Stimulation of the ovary with hormones together with ovulation induction. Although artificial insemination may be carried out taking advantage of the natural cycle (without ovarian stimulation), ovarian stimulation with hormones causes various follicles to develop, which after pharmacological ovulation induction means more than one ovum (egg) is available to be fertilised naturally. Thus, the possibility of achieving pregnancy is increased.
- The preparation of semen consists of selecting and concentrating the mobile spermatozoa, since their low mobility (“motility”) would have a negative effect on the possibility of achieving pregnancy. This is why the specimens are processed by means of semen capacitation or preparation techniques. Cell remains and dead, immobile or slow spermatozoa are eliminated from the ejaculate using the techniques of washing and capacitation.
- Insemination is carried out in the consultation visits: it is not necessary to use any kind of anaesthesia as the process is painless. Insemination is usually performed after inducing ovulation. It is necessary to provide the laboratory with a semen sample. Once the sample has been prepared, it is deposited in the uterus by means of a special cannula. After the semen is deposited, the woman must rest for a few minutes.
As regards the results obtained in IVI with artificial insemination, when talking about semen from the couple the gestation rate per cycle is about 20%. In other words, for every 100 cycles nearly 20 result in pregnancy, and for every 100 couples that complete 4 cycles, 60 manage to conceive.
What are we looking for in artificial insemination treatment?
- Ensuring ovulation. Although artificial insemination can be considered during a natural cycle, the efficiency of insemination increases when we use exogenous gonadotropins that induce multiple follicle development. This development is controlled by means of transvaginal ultrasound scans and the determination of estradiol levels in the blood, until the suitable moment is determined for triggering ovulation (administering the hCG hormone). Insemination is carried out the day after the hCG is administered.
- Improving and increasing the potential of the spermatozoa. To attain a better semen quality, different washing techniques are used that eliminate seminal plasma, cell remains and dead, immobile or slow spermatozoa from the ejaculate. Finally, the spermatozoa population with the highest motility and fertilising capacity is concentrated in a small volume. The two techniques most often used for this process are the swim up technique (the fastest spermatozoa swim up in a fluid medium) or the density gradient technique (the fastest spermatozoa are able to overcome different gradient densities while the plasma and cell remains are retained).
Which couples can choose artificial insemination?
- Couples whose reasons for sterility are unknown, in other words those that have undergone a basic sterility study (which includes a seminogram for the man and an ultrasound scan, basal hormone analysis and hysterosalpingogram for the woman) and the cause has not been found.
- Couples where the woman does not ovulate correctly (which happens more often in those affected by polycystic ovary syndrome), or else she has defects in the cervical mucus which make it a hostile environment for the spermatozoa.
- Couples where the man has slight defects in his semen. For example, the concentration or motility is not sufficient (oligozoospermia or azoospermia) or, though this occurs less often, there is an anomaly in his genitals that hinders coitus or makes ejaculation difficult.