| In a natural ovulation cycle, one ovum is releases every month. Using IVF techniques, the chance of achieving pregnancy is improved by increasing the number of ova. To this end, drugs are administered to induce ovulation. These drugs contain Follicle Stimulating Hormone (FSH) and stimulate the ovaries to produce a larger number of oocytes. The drugs are given in daily injections and include Gonal F, Puregon, Menogon, Metrodin and others. Other drugs are used to prevent early ovulation, including Decapeptyl, Buserelin, Cetrotide; these are given by injection or nasal spray. Rarely, oral drugs such as Ikaclomin are used to induce ovulation, but they are generally less effective compared to injectable drugs. Different protocols for ovulation induction exist, employing different combinations of these drugs.
The response to treatment is individual, unpredictable and may change from cycle to cycle in the same patient. Therefore, treatment is determined individually and may be altered from cycle to cycle according to previous response patterns.
The patients' response to ovulation induction is monitored by blood tests for hormones produced by the follicles in which oocytes develop (estradiol=E2 and progesterone) and by vaginal ultrasound scans which follow the developing follicles. When follicles reach the appropriate size, the patient receives an injection of Chorigon (LH) required to complete the ooocyte's maturation. 34-36 hours later, the patient undergoes ovum pick up.
The duration of ovulation induction, from the first day of menstruation until ovum pick up, depends on the protocol used, and may be as short as 12-14 days or as long as three-four weeks. |
