Letrozole is taken to stimulant ovulation in women who are having difficulty conceiving. If the course of letrozole is successful (results in ovulation), then ovulation should occur along the normal time course of your menstrual cycle: approximately 12 to 16 days after the first day of your menstrual bleeding.

There are ways to monitor for ovulation to determine when the best chance is to conceive.

Infertility is the inability to get pregnant after 1 year of having sexual intercourse on a consistent basis without the use of birth control. The most common cause of female infertility is problems with ovulation.

Letrozole is used to stimulate ovulation. It does this by affecting certain female hormone levels. Once successful ovulation is achieved, the egg may be fertilized through timed sexual intercourse, intrauterine insemination or in vitro fertilization.

The normal menstrual cycle consists of three phases. The second phase is called the ovulatory phase. It occurs anywhere between 12 and 16 days after the first day of menstrual bleeding. When you take letrozole to stimulate ovulation, it supports this normal timeframe of ovulation if it works.

There are several ways to monitor ovulation:

• Blood samples may be taken to measure hormone levels.
• An ultrasound of the ovaries may be performed to look at the follicles where a woman's eggs reside and mature.
• Your body temperature rises just after ovulation, so body temperature may be tracked.
• There are also home ovulation-predictor kits that measure the levels of a hormone called luteinizing hormone in your urine.

In a study that looked at the use of letrozole for stimulating ovulation, women with polycystic ovary syndrome were permitted to take up to 5 courses of letrozole in an attempt to conceive. In the study:

• About 62% of all letrozole treatment cycles resulted in ovulation
• About 89% of the women taking letrozole successfully ovulated
• About 41% of the women conceived