What is Letrozole Used For?
Letrozole (Femara) is an oral medication originally designed as a treatment for breast cancer that is used as an off-label fertility drug. Letrozole can be used to stimulate ovulation, treat unexplained infertility or treat patients with polycystic ovary syndrome (PCOS) symptoms. Letrozole’s use will depend on your fertility diagnosis or previous treatment history. If you are having irregular or infrequent ovulation, or have unexplained infertility with normal ovulation, your fertility treatment may begin with your doctor prescribing the medication Letrozole, frequently known by the brand name Femara. It is the second most commonly used for medication for ovulation induction after Clomiphene citrate (Clomid). Other treatment options or fertility drugs given for ovulation induction
How Does Letrozole (Femara) Work?
Letrozole is an aromatase inhibitor that works by inhibiting the enzyme aromatase. This blocks the production of estrogen in the body. Since the hormone receptors in the brain do not detect estrogen, it causes the pituitary gland to respond by producing more follicle-stimulating hormone (FSH). Increased FSH results in ovarian stimulation and can result in the development of multiple eggs.
What Is Letrozole Used For In Infertility?
In women who are ovulating normally, Letrozole can stimulate the development of multiple follicles and eggs to be released, often known as controlled ovarian hyperstimulation or superovulation. This improves your chance of pregnancy as compared to a natural menstrual cycle where only one egg is released, especially when combined with intrauterine insemination. For patients with PCOS (Polycystic ovary syndrome) it is considered more effective than Clomiphene citrate (Clomid) and also reduces the risk of twin or multiple pregnancy because less follicles (which contain eggs) develop without a reduction in pregnancy rates compared to Clomiphene citrate (Clomid).
It is typically prescribed by your healthcare provider for a treatment course of 5 days starting 3 or 5 days after the first day of your menstrual cycle. The dose can range from 1-3 tablets (2.5 mg per tablet) of letrozole per day. Your fertility physician will then ask you to use ovulation kits and check the development of the follicles (where the eggs mature in ovary) with an ultrasound on day 12, 13 or 14 after your menstrual cycle starts. Once it has been determined that you have 1-3 mature follicles on ultrasound, your physician will advise you to use hCG to release the eggs and have intrauterine insemination or timed intercourse afterwards. Intrauterine insemination doubles success rates by allowing sperm to bypass the cervical mucus where they can get trapped. Once ovulation occurs, the eggs have 24 hours to be fertilized within the fallopian tubes. It may be recommended that you take progesterone after insemination or intercourse while you wait for your pregnancy test results.
What Are The Side Effects Of Using Letrozole During Infertility Treatment?
The side effects of letrozole include headaches, nausea, hot flashes, breast tenderness and abdominal bloating. Letrozole tends to have less side effects than Clomiphene citrate. There is no increased risk of congenital malformations (birth defects) when using Letrozole compared to Clomid.
Does Letrozole Help You Get Pregnant?
Ovulation rates and pregnancy rates using Letrozole (Femara) can be increased compared to at home conception if you are not ovulating, or if you have unexplained infertility, especially when it is combined with intrauterine insemination. It is an effective treatment for women with polycystic ovary syndrome (PCOS) and can be combined with metformin which helps reduce insulin and androgen levels. Typically 2-3 cycles of letrozole is recommended before considering another fertility treatment such as IVF (In Vitro Fertilization).