Ovulation Induction (OI)
The purpose of Ovulation Induction (OI) is to produce multiple eggs to increase the likelihood of conception. For women who do not ovulate regularly, oral or injectable medications may be administered to support oocyte or egg development.
How does ovulation induction work?
For women who are not ovulating or who have irregular menstrual cycles or unexplained infertility, ovulation-inducing medications are often the first method physicians will try to achieve pregnancy. Medications stimulate the release of hormones that drive egg production. (Sometimes another hormonal injection is used to trigger ovulation, although some women wait for that to happen naturally.)
There are two types of ovulation induction medications:
Oral medications. These are usually the first line of treatment for women who do not ovulate or who ovulate infrequently.
A typical treatment cycle begins with an ultrasound and blood work on the third day of the menstrual cycle. Clomiphene (Clomid) and letrozole (Femara) are oral medications taken between days three and seven or between days five and nine of your cycle. A transvaginal ultrasound will be performed on day 10 or 11 to check for egg development.
In the ovaries, each egg is contained within a follicle, or fluid-filled sac, that can be visualized by ultrasound. When a woman ovulates, the follicle releases a then-mature egg. (Several follicles develop in the ovaries during each cycle, but usually only one will release an egg.)
Injectable medications: If oral medications are unsuccessful, injectable medications such as a follicle-stimulating hormone (FSH) are typically the next step. The treatment cycle begins with an ultrasound and blood work on day three of the menstrual cycle. Injectable medications are started on day three and are continued for six to 10 days, depending on response.
During that time, you may require three to four ultrasounds and blood work to monitor the development and pace of the follicle growth. After each visit for ultrasound and bloodwork, you will receive a phone call from the nurses with follow-up instructions.
Once the lead follicle/s measure at least 16 to 18 millimeters in diameter, you will be instructed to take an injection of human chorionic gonadotropin (hCG), which triggers ovulation. IUI or intercourse can then be performed to achieve conception.
- The Ovulation Induction Process
- Who is a good candidate for ovulation induction?
- How is ovulation monitored during the induction process?
- What to Expect
Ovulation-inducing medications taken by mouth may be used in conjunction with an Intrauterine Insemination (IUI) or In Vitro Fertilization (IVF) procedure, or on their own to help boost your natural ability to get pregnant. Oral medications are usually the first line of treatment when a doctor initially addresses your infertility concerns.
If the oral medication regimen does not produce a pregnancy, you may be prescribed injectable ovulation-inducing drugs. While less convenient than taking a pill, injectable medications are considered more effective.
Women with irregular ovulation or anovulation (lack of ovulation) are often good candidates for ovulation induction. Your fertility specialist can help determine if this treatment is right for you.
Monitoring involves regular blood tests and ultrasounds to track follicle development and hormone levels, ensuring the treatment is progressing as expected.
Natural ovulation usually produces one egg. OI medications stimulate many follicles in the ovaries so that several eggs mature at once. While taking the medication, we will use blood work and ultrasound to monitor the development of your follicles (egg sacs) in order to determine the right time for an insemination or egg retrieval. Once the follicles are fully developed and the eggs are mature, your doctor will perform either an IUI procedure, where sperm is inseminated into the uterus, or an egg retrieval procedure, where egg and sperm are fertilized outside the body.
If you are using an OI medication to conceive naturally, monitoring can also help you schedule the best time for sex.