Ovulation induction involves the controlled administration of fertility drugs to stimulate the ovary to produce one or multiple eggs, depending on the circumstances.
Ultrasound scans and blood tests are usually done frequently in cycle monitoring to:
1) ensure that you are responding to the medications appropriately and
2) to time intercourse or artificial insemination (IUI).
There are two classes of fertility drugs commonly used in ovulation induction.
First type:
These drugs are given in tablet form and include drugs like Clomiphene Citrate (Clomid or Serophene) and Letrozole (Femara). Clomiphene and Letrozole work by stimulating your pituitary gland (in your brain) to release more of your own follicle stimulating hormone (FSH), which is the hormone required for follicle and egg development. Normally, this is given in a short course at the beginning of the menstrual cycle for 5 days. When the egg(s) is/are found to be mature, an additional hormone injection called human chorionic gonadotropin (hCG) (Ovidrel) can be given to trigger the release of the egg(s) from the follicle(s).The risk of twins with oral fertility medications is approximatelyaround 5%.
Second type:
This includes fertility drugs in the form of a hormone injection known as a gonadotrophin (these contain a purified form of FSH and possibly some luteinizing hormone (LH)). There are a variety of gonadotrophin preparations available (some common names include Gonal-F, Puregon, and Repronex). Gonadotrophin injections are given daily to stimulate the development of mature follicle(s). Egg release is then triggered with an hCG injection (Ovidrel) when the follicle/follicles has reached an appropriate size.
When injections are used alone or overlapping with oral medications, the risk of multiple pregnancy increases to 10-20%.
Please note: The success of ovulation induction treatment depends on many factors, including age, sperm count, presence of endometriosis, etc. It often takes 3-4 cycles (each cycle takes one month) of ovulation induction treatment to conceive. If conception does not occur with this method, your doctor will review your chart with you and may recommend other treatment options.