Drug treatment for infertility
A prerequisite of fertilization is that the pituitary gland, the ovary and the uterine lining to be functional.
Until the mid-twentieth century, due to the lack of appropriate knowledge and training, the treatment of infertility was experimentally performed. For the first time in 1945 animal hormones were used in the first part of the cycle, and under their action appropriate uterine lining was obtained for fixing and fertilization. Due to the rapid development of hormonal examination methods, the explosive development of the ultrasound diagnosis and the worldwide spread of the in vitro fertilization method, the extensive use of drug therapy has gained a large popularity.
The cause of infertility is most often a hormone producing disorder of the ovarian function and is can be effectively treated with drugs or surgery. In these cases, the consequence is the lack of ovulation, behind which lies a disorder in the functioning of the brain-midbrain-pituitary gland-ovary axis, but the problem may involve anomalies of other endocrine organs (such as the thyroid gland, adrenal gland).
As it is known, in 25-30% of the cases behind female infertility lie the anomalies of ovulation, out of which the most important is the polycystic syndrome (PCOS), but also different lifestyle habits, excessive sports and diets, stress, obesity can cause disorders of the menstrual cycle, and, as a consequence, sterility.
Regarding the action mode of different medications, we can say that these compounds connect to the receptors which detect female hormones (estrogen) in the midbrain (hypothalamus), thus indirectly increasing the activity of the ovary. The active substance of these medicines is clomiphene citrate, which has been the medicine widespread used for the stimulation of the ovarian activity since the beginning of the 1960’s. The advantage of the drug is that it can be used orally, has significantly lower price compared to other medicines used for stimulation and its use doesn’t require an intensive clinical observation. Selecting the patients who respond well to the treatment is a serious task of the specialist doctor; otherwise it’s necessary to consider a low degree of efficiency and a low pregnancy rate.
Decreasing prolactin level
In many patients an increased prolactin level can be noted, the hormone responsible for lactation. In an important part of the cases it has a functional origin (e.g. increased desire to have children, stress conditions etc.). Before beginning a prolactin lowering therapy the presence of pituitary gland hormone producing tumors must be excluded. In cases with severe pathological prolactin elevations, besides the nipple discharge (leakage of a liquid similar to milk), ovulation does not occur, the menstruation is missing and consequently, infertility develops.
Insufficiency of the corpus luteum
The notion of ovulation disorders is in fact a collective notion, which also includes the functional anomaly of the corpus luteum, produced after the ovulation. In order to eliminate these problems, in the second part of the cycle we can use preparations containing progesterone, for example after the previously mentioned therapy, or in the case of an unknown origin infertility. Most modern formulas are suitable for being introduced into the vagina, thus bypassing the liver, and they are absorbed without general side effects and directly bind to the uterine lining. Besides a lower blood concentration, we can obtain a higher pregnancy rate and we can reduce the frequency of abortions.
These are medicines which act directly on the ovary: these are gonadotropic hormones which may be used in the form of injections. These are mostly obtained from the urine of menopausal patients, while the most recent medicines, which are still rather expensive, are produced with the use of genetic technology. These so-called recombined preparations have several advantages despite their high costs: their use increase the chance of fertilization even by about 30-35%. Since duration of treatment can be shortened, their cost-effectiveness has shown to be improved.
Drug therapies can also have side effects. First of all, overstimulation (the ovarian hyper - stimulation syndrome [OHSS]) and ovarian cysts can develop. The mild forms of overstimulation resolve spontaneously (accompanied by mild hypogastric pain), while average and severe forms can be treated only with appropriate treatment, with or without hospitalization and including effective therapies. Without this treatment, complications may occur, even life threatening events. Another disadvantage of overstimulation is that in 20-40% of cases after drug treatment multiple pregnancies can occur. For this reason it is very important that the controlled ovarian stimulation must be initiated by an experienced specialist, based on the appropriate indications. During therapy repeated ultrasound exams and several hormone measurements might be necessary, as these assessments provide an individualized and more effective treatment.