
Ovulation problems are a common cause of infertility for women. There are several reasons why a woman may not be ovulating or is ovulating irregularly, all of which make it difficult to become pregnant.
Ovulation is when a mature egg is released from the ovary. The egg travels to the fallopian tube, where it can “mix” with or be fertilized by sperm.
If the egg is fertilized, the resulting embryo travels to the uterus, a journey that takes several days. If the embryo implants, you’re pregnant. If it doesn’t, you’ll have your “period.”
Ovulation induction uses fertility medications to stimulate the release of one or more eggs from the ovary. Sometimes, a procedure called intrauterine insemination (IUI) is used in conjunction with ovulation induction to achieve pregnancy. IUI entails placing washed, concentrated sperm directly into a woman’s uterus via a small catheter.
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 and letrozole 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 reached the satisfactory size, 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.
How successful is ovulation induction?
Success depends on the woman’s diagnosis and other factors, including her age. “In general, we achieve a 20 to 25 percent success rate of pregnancy per cycle,” she says. “And it’s important to note that the chance of any pregnancy in a young, healthy couple with no fertility issues is, at best, about 20 percent each month.”