Ovulation-related problems can be corrected by administering hormonal preparations or ovulation inducers.
These treatments are used in the following situations :
- To trigger ovulation in women who do not ovulate spontaneously ;
- To control the time of ovulation ;
- To correct post-ovulation hormone problems ;
- To stimulate the production of several oocytes per cycle.
The latter effect is sought after in in-vitro fertilisation and in intra-uterine insemination in an attempt to promote the chances of fertilisation and therefore pregnancy by multiplying the number of oocytes available.
Clomifene
Clomifene (Clomid®, Serophene®) is the most widely prescribed ovulation inducer in the world. It is generally given to women with long, irregular cycles. The usual dose is 1 to 2 x 50-mg tablets a day for 5 days. An ultrasound scan is carried out prior to treatment in order to rule out the possibility of an ovarian cyst, which would constitute a contra-indication. (To find out more)
hMG and FSH
FSH is a gonadotropin secreted by the pituitary gland that triggers the follicular development and maturation of an oocyte in a normal ovarian cycle. After the menopause, FSH and another hypophyseal gonadotropin, namely LH, are secreted in large quantities in the urine. hMG (human menopausal gonadotropin) is a preparation purified by the urine of menopausal women. It contains a mixture comprising equal parts of FSH and LH. Several hMG preparations are currently available (Merional®, Menogon®, Menopur®). The administration of hMG in the form of subcutaneous injections directly stimulates the ovary. It is used in women who do not ovulate spontaneously and who fail to respond to clomifene, or to stimulate multifollicular development in women with a normal ovulation cycle with a view to insemination or in-vitro fertilisation. (To find out more).
hCG
The human chorionic gonadotropin (hCG) is produced by the placenta. It is the principal pregnancy hormone. It is excreted in large quantities in the urine of pregnant women from which it can be extracted by purification. The molecular structure of hCG is very similar to that of LH, the hypophyseal gonadotropin that triggers ovulation.
The administration of an injection of hCG (Choriomon®, Ovitrelle®, Pregnyl®, Profasi®) at the end of ovarian stimulation mimics the natural peak of the LH. It triggers the rupture of the mature follicle and oocyte release 36 to 40 hours post-injection.
