Ovulation Induction

Doctors use the term “infertility” when a couple is unable to become pregnant after one year of unprotected sex. In any given year, approximately 15 percent of couples who are trying to conceive have infertility.

About once a month, an egg is released by one of the ovaries; this is called “ovulation.” The egg travels down the fallopian tube, and if it is fertilized by a partner’s sperm, pregnancy begins.Some people have infertility because they do not ovulate regularly or at all. A common cause of this is polycystic ovary syndrome (PCOS). In other cases, the person does ovulate, but still has trouble getting pregnant. In either of these situations, treatment with hormones can stimulate the body to ovulate, which increases the chances of being able to conceive. Doctors call this “ovulation induction.”

Before beginning any treatment for infertility, it’s important that you and your partner both be evaluated in order to identify any potential causes and develop a treatment plan. This evaluation may include a complete history and physical examination, a semen analysis (for the male partner), blood testing, and other tests depending upon the individual situation. If it is determined that you are not ovulating, this means you will need medical intervention to get pregnant; treatment should be initiated soon after the initial consultation and evaluation.

Health care providers can prescribe two different oral (pill) medications for ovulation induction: clomiphene and letrozole.

Clomiphene—Clomiphene is a weak estrogen-like hormone that acts on the hypothalamus, pituitary gland, and ovary to increase levels of certain hormones responsible for ovulation.
Letrozole—Letrozole is a medication that is used in the treatment of breast cancer; however, it also works for inducing ovulation. Many health care providers recommend that people with PCOS try letrozole first because studies have found it to be more effective.

Here are two categories in which treatment with clomiphene or letrozole may be recommended:

People who do not ovulate at all or who ovulate irregularly due to PCOS—The goal is to induce ovulation and increase the chances that the person will conceive a pregnancy.
People who ovulate normally but are having trouble getting pregnant—in this group, clomiphene is usually tried first, along with intrauterine insemination (IUI).

How to take this medication?

The exact protocol and schedule will depend on which medication your health care provider has prescribed as well as your individual situation.
Before starting medication — If you have polycystic ovary syndrome (PCOS) and have excess body weight or obesity, your provider may suggest trying to lose weight before taking medication to induce ovulation. Losing 5 to 10 percent of your body weight may lead to more regular periods and the return of ovulation without medication. Your provider can talk to you about your options for weight loss if this is something that could benefit you.

Medication dosing and schedule — The dose will depend on which medication your health care provider prescribes. With both clomiphene and letrozole, the dose can be increased over time if ovulation induction does not result in pregnancy.

When you take the medication will depend on where you are in your menstrual cycle:

The first day of menstrual bleeding is considered day 1 of the cycle. Some people who do not have regular menstrual cycles will take a hormone called progestin to help induce a period.
Clomiphene is usually started on day 3, 4, or 5 of the cycle. Letrozole is started on day 3. In either case, you continue taking the medication once a day for five days.
Ovulation usually occurs between cycle days 14 and 19. Most fertility specialists recommend using an ovulation predictor kit in order to know when your body is preparing to ovulate. These kits use a urine sample to measure hormone levels; they are available without a prescription in most pharmacies.
You will be instructed to have sex on specific days to maximize your chances of getting pregnant. Many providers suggest having sex every other day for one week beginning five days after the last day of medication. Using an at-home ovulation predictor kit can also help you identify the optimal time to try to conceive. In some cases, the next step might be intrauterine insemination (IUI) instead of trying to conceive through sex.
Some health care providers recommend monitoring with pelvic (transvaginal) ultrasound. This involves inserting a thin probe into the vagina and using sound waves to view the size and number of developing follicles (which contain an egg). Your provider might also order a blood test later in your cycle to confirm that ovulation has occurred.

Benefits :

The benefit of these medications is that they are relatively inexpensive and can be used before other, more expensive testing (such as hysterosalpingogram or laparoscopy) or infertility treatments (eg, gonadotropin therapy, in vitro fertilization [IVF]). People using them do not absolutely require monitoring with ultrasound or blood hormone levels, although many health care providers do monitor with ultrasound. Clomiphene improves the chances of becoming pregnant for most people who ovulate irregularly, and it carries a low risk of dangerous side effects. In addition to anovulation, clomiphene is also administered in conjunction with intrauterine insemination in unexplained infertility.

Risks :

Risks of clomiphene therapy include a slightly increased rate of multiple pregnancies; approximately 6 percent of people who use clomiphene have twins, while less than 0.5 percent have triplets or greater. There is a small risk of the ovaries becoming enlarged, although severe enlargement (known as ovarian hyper stimulation syndrome [OHSS]) is rare.
Uncommon side effects of clomiphene include hot flashes, headaches, and mood changes. Visual symptoms such as blurring, double vision, or seeing spots occur in 1 to 2 percent of cases, and usually resolve when treatment stops.
Most studies do not show an increased risk of birth defects, pregnancy loss, or learning disability in children of women who took clomiphene or letrozole. There is no evidence of an increased risk of breast, uterine, or ovarian cancer.