Getting Pregnant with Letrozole for Fertility

Struggling with infertility is stressful. However, recent advancements in fertility care treatment can help improve your chances of becoming pregnant. One option is oral medications that help with ovulation. Letrozole is one of a few different medications available for this purpose, known by its brand name, Femara. This article reviews how letrozole works, when it may be prescribed, and things to consider when taking it.

What is Letrozole?

Letrozole is an oral medication typically used to treat breast cancer but may also be prescribed as a fertility treatment to induce ovulation. Patients with irregular periods or ovulation disorders can benefit by taking letrozole. Letrozole may also be used to preserve fertility in people with estrogen-sensitive cancers, as it blocks estrogen production. This can slow the growth of certain types of breast cancers that need estrogen to grow.

Letrozole has been approved by the Federal Drug and Food Administration (FDA) to treat estrogen-sensitive breast cancer in postmenopausal women. It has also gained popularity for treating infertility, which is considered an off-label use. Letrozole is still considered safe to use for infertility because your body clears the medication from your system before you become pregnant. Taking this medication during pregnancy is unsafe, as it may cause congenital disabilities in a fetus.

Some providers may recommend using letrozole in ovulatory patients to increase their chances of becoming pregnant. Fertility specialists might suggest letrozole for patients with endometriosis, pelvic factor infertility, or advanced maternal age.

Using Letrozole to Get Pregnant

Letrozole treats infertility caused by ovulation disorders such as polycystic ovarian syndrome (PCOS). PCOS is a disorder that causes hormone imbalances and can result in irregular or no ovulation. Letrozole is also used to treat patients with unexplained infertility to promote ovulation. Your fertility specialist may recommend adding letrozole to your treatment if you are undergoing intrauterine insemination (IUI) and in vitro fertilization (IVF).

Letrozole is used to lower estrogen levels in your body by blocking aromatase. When estrogen levels decrease, your body secretes hormones that induce ovulation.

The Letrozole Treatment Process

A young woman looking at a bottle of fertility medication

Letrozole may be used to help you get pregnant with timed intercourse or intrauterine insemination (IUI) if you have:

• Unexplained infertility

• Co-administration during controlled ovarian stimulation

• Prevention of ovarian hyperstimulation syndrome (OHSS)

Polycystic ovarian syndrome (PCOS)


• Fertility preservation

Dosage and Administration

Letrozole may be used alone or with follicle stimulating hormone (FSH) to induce ovulation. Typically, letrozole is taken in doses ranging from 2.5 to 7.5 mg daily, and for a five-day course, it should be taken at the beginning of your menstrual cycle. One of our fertility experts will instruct you on your dosing.

Letrozole in Combination with Assisted Fertility Treatments

Letrozole may be given during controlled ovarian stimulation to increase certain hormone levels in the fluid within the ovarian follicles, which helps improve their response to follicle stimulating hormone (FSH). FSH stimulates follicles in the ovaries to prepare your eggs for ovulation. The follicles release estrogen and small amounts of progesterone into your bloodstream as they grow.

Studies have shown that when letrozole is taken with IUI, IVF, and frozen embryo transfer (FET), it can increase the chances of a successful pregnancy and live birth. Letrozole can also improve your response to gonadotropin medications commonly used with IVF. Because of this evidence, fertility specialists may recommend taking letrozole if your treatment plan includes IUI, IVF, or FET.

Letrozole in Conjunction with Intrauterine Insemination (IUI)

Intrauterine Insemination (IUI), also known as artificial insemination (AI), is when a fertility specialist places a specially prepared sperm sample directly into your uterus. This treatment can treat male or female infertility. Fertility specialists sometimes recommend using letrozole during IUI to accompany ovulation induction cycles and help increase the chances of pregnancy.

Letrozole as an Adjunct to In Vitro Fertilization (IVF)

A patient discusses her fertility treatment with a fertility specialist in a doctors office

During IVF treatment, fertility specialists may recommend letrozole to help regulate the menstrual cycle and improve the chances of successful ovulation and fertilization. For some patients, letrozole can help improve your response to gonadotropin medications commonly used during IVF.

Fertility specialists may also recommend taking letrozole if you are preparing for frozen embryo transfer (FET). Successful FET depends on your endometrium's receptivity and its synchronization with embryo development.

If you are considering IVF, your fertility specialist will determine if letrozole is an appropriate option to add to this treatment based on your medical history and individual circumstances. If your fertility specialist prescribes letrozole, they will closely monitor your response to ensure correct dosing.

Comparing Letrozole to Other Fertility Medications

Clomiphene citrate (clomid) is a first-line infertility treatment for ovulation induction and is used for many cases of infertility and ovulatory dysfunction. Letrozole is a first-line treatment specifically for patients with a PCOS-related ovulation disorder. In patients with PCOS, taking letrozole has demonstrated higher pregnancy and live birth rates than those taking clomid. Both medications are considered safe for ovulation induction and can cause mild side effects while taking them. While on clomid, you may experience hot flashes; while on letrozole, you may experience fatigue or dizziness.

Success Rates and Considerations

In a study, 750 women were randomly assigned to two control groups. One group received clomid 50 mg daily, and the other group received letrozole 2.5 mg daily. Both groups received the medication for five days of their early menstrual cycle for up to five menstrual cycles. In both treatment groups, if there was no response or poor ovulatory response, the dose was increased in their next cycles. The results showed that letrozole was more effective than clomid in helping women with PCOS-related ovulation disorders become pregnant. The research also found that patients with PCOS who were treated with letrozole were more likely to ovulate and have a live birth than those treated with clomid.

Risks and Side Effects

Common side effects of taking letrozole include:

• Hot flashes

• Joint pain

• Flushing

• Tiredness

• Headache

• Dizziness

You should discuss the option of using letrozole with your fertility specialist. They will review any other medications that you are currently taking to determine if it is safe for you to take letrozole. Letrozole can effectively stimulate ovulation and increase the chances of a successful pregnancy and live birth.

An Option for Infertility

Your physician may include letrozole in your treatment plan if you struggle with an ovulation disorder that negatively impacts fertility. It is essential to consider what other medications you are actively taking before starting letrozole, as it may interact with or affect your hormone levels. Letrozole is safe for most people to take, but you may experience mild side effects that are usually hormone related.

If you're ready to begin your fertility journey to parenthood, talk with one of our fertility specialists today to discuss your treatment options.

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