The success of artificial insemination depends on the accuracy with which the precise moment in which the trained spermatozoids are to be deposited in the fundus of the uterine cavity. According to specialists in Assisted Reproduction , if the spermatozoa arrive too soon to the place where the ovum is, when it arrives, the spermatozoa will no longer be able to fecundate.
Similarly, if sperm reach the egg long after ovulation, fertilization will not occur either because of the changes that have already occurred in the female gamete.
Therefore, in order to perform an artificial insemination, the specialists monitor the patient to identify the most appropriate time for fertilization .
Artificial insemination: control of ovulation
In order to improve the chances of success of artificial insemination, the development of the follicles must be previously controlled and the time of ovulation. This monitoring of follicular development is performed by transvaginal ultrasound and estradiol determinations in blood.
Ultrasounds are usually performed from day 6 or 7 after the onset of menses to measure the size of the follicles (cysts in the ovaries filled with fluid that contain oocytes and that increase from rule to ovulation), And count how many of them have been developed.
Physiologically, in women who have normal ovarian function, a single follicle of the 8 or 10 that begins to grow every month develops completely. At the beginning of the artificial insemination cycle the growth of more follicles is induced , administering a treatment that causes more hormones to reach the ovary, so that more than one can develop completely.
In women with normal ovulation it would be possible to perform artificial insemination without this hormonal treatment, but ovarian stimulation increases the chances of gestation , since it allows better control of the cycle and makes the endometrium (mucosa that covers the cavity of the uterus) more receptive and , Since there are more eggs, there are more chances that some of them will be fertilized by some spermatozoid.
Risks of artificial insemination
Having several ovules increases the pregnancy rate but also the multiple pregnancy. To avoid this problem, the specialist should perform ultrasound checks to see the size of the follicles and know how many go forward, canceling the cycle in cases where the ovarian response is excessive, since then the risk of complications or multiple pregnancy Can be high.
However, it happens that not all the follicles that are developed have the same level of maturity, not all ovulate at the same time. In order to assess the degree of maturity, in addition to the ultrasounds, determinations of estradiol in blood , one of the hormones that are produced in the follicles. Thanks to ultrasound measurements and blood estradiol values, as well as to the continuity of these tests, it is possible to calculate, exactly two days in advance, when exactly ovulation occurs, and artificial insemination can be programmed at that moment.
Personalization of artificial insemination treatment
The treatment for artificial insemination administered, the number of ultrasounds and blood tests, the day they are performed, etc.. Is completely customized for each patient and for each cycle of treatment in particular, depending on the data of the particular clinical history, as well as the ovarian response to the stimulation that has been seen in previous cycles. Two ultrasounds and one or two oestradiol determinations are often sufficient to calculate when the egg is fertilized, but each case requires customizing treatment and control of ovulation.