Letrozole for Ovulation Induction

Letrozole belongs to a class of drugs called aromatase inhibitors.

The prime and only licensed use of Letrozole is as an additional (adjuvant)
treatment of breast cancer in post-menopausal women. It is, however, being
increasingly used as a treatment by fertility specialists to aid the development of
ovarian follicles.

Letrozole can be considered for use in the following situations:

  1. If you have not responded to Clomiphene citrate (Clomid) ovulation induction
    treatment
  2. If you persistently develop more follicles to ovulation induction treatment
  3. If you are unable to tolerate Clomiphene citrate (Clomid)
  4. If the normal development of the lining of the womb is affected by Clomiphene
    citrate (Clomid) treatment
  5. As an adjuvant medication in patients with breast cancer undergoing IVF for
    fertility preservation before they undergo chemo- or radio-therapy

Letrozole is taken as a tablet from day 2-6 of the menstrual cycle.

What are the advantages of taking Letrozole?

Many studies have recently shown that using Letrozole for ovulation induction
results in better rates of successful ovulation and has no adverse effects on the
lining of the womb, something seen with Clomid, resulting in higher birth rates
than with standard treatment. Letrozole is also associated with more cycles where
only one follicle develops and hence lower multiple pregnancy rates compared
with clomiphene (3.4% v 7.4% respectively).

Are there any risks with Letrozole?

The risk of congenital abnormalities in babies appears to be lower than with
clomiphene and is comparable with babies conceived naturally.

Are there any side effects?

The most common side effect of taking Letrozole is hot flushes, as well as
occasional fatigue and dizziness.

Treatment with Letrozole is off-license as the drug company has not applied for
a specific license to allow treatment for fertility and is therefore not approved for
ovulation induction.

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Letrozole for Ovulation Induction