Ovulation induction treatment with Letrozole

Patient Information Leaflet

What is Letrozole?

• Letrozole is a fertility drug used to help patients conceive a baby.
• The drug works by stimulating the ovary to produce more follicles.
• Follicles are fluid filled sacs inside the ovaries where the egg develops.
• In this way, Letrozole helps with the release of an egg ready for fertilisation (ovulation).

What are the possible side effects and risk of treatment?

• The main side effects can include abdominal (stomach) pain, alopecia (hair loss), gastro-intestinal (gut) changes, joint pain, mood change, dry skin, headache and hot flushes
• There is a small risk of multiple pregnancies.
• There is a rare risk of ovarian hyperstimulation (OHSS).
• This is when the ovaries become enlarged with multiple follicles, causing symptoms of abdominal discomfort and bloating.

How effective is Letrozole?

• Most women will ovulate during the six months of treatment.
• The pregnancy rate is about 30 percent. About one third of patients will get pregnant.

What is the treatment process?

Day one of menstrual cycle

• Telephone the fertility nurses on 020 7288 3776 to arrange a scan.
• Please leave a message if the Nurses are not available.
• Alternatively, you can email the team: whh-tr.fertilityunit-whitthealth@nhs.net

Day two of the cycle

• Start Letrozole as advised by the fertility team.

When do I start Letrozole if I have irregular cycles?

• If your periods are irregular, you may be given a medicine called Provera. It can help bring on a period.
• You will need to take a pregnancy test before taking Provera.

Scanning during the treatment process

• Your first scan may be between days 9-12 of your cycle.
• Your scan will take place in Clinic 4C. You will need to make an appointment.
• The scan is done by gently placing a small device inside the vagina (transvaginal) to look at the womb and ovaries.
• You will need to have an empty bladder for the scan.
• At each scan, the lining of the womb (endometrium) will be measured.
• Each ovary will also be assessed, and the size of the follicles measured.
• The fertility Nurses will explain the scan results to you.
• You may need up to six scans over a 2-week period.
• Your fertile period is when your follicle(s) are found to be 17mm or more.
• You will be advised to have sexual intercourse on alternate days during this time as this is your best chance of conceiving.
• Some patients may require a ‘trigger’ injection (hCG injection). This helps the follicle to release the egg.

What happens if I do not conceive?

• If the scans and blood tests show that you have responded well and ovulated in your first cycle, continue to take Letrozole in your next menstrual cycle.
• Please contact the fertility Nurses for a further prescription of Letrozole.
• We will continue to monitor each cycle with scans.

What do I do if I have not responded to Letrozole?

• If the scans show that the ovaries have not responded to Letrozole, the dose of Letrozole can be increased or other medications can be tried.
• The treatment will be monitored by scans.
• Please do not change your dose without instruction from the fertility team.

What do I do if I have over-responded to Letrozole?

• If the scans show that your ovaries have over-stimulated, the dose of Letrozole may be reduced in your next cycle.
• We will tell you not to have sexual intercourse. This is to avoid the risk of multiple pregnancies.
• Please let the fertility team know if you feel unwell.

What do I do if I have a positive pregnancy test?

• If you have a positive pregnancy test, please let the fertility Nurses know on 020 7288 3776.
• They will arrange for you to have a scan at 7 weeks to confirm the pregnancy.

Contact our service

The Fertility Centre
Tel.: 020 7288 3776 (Monday to Friday 9am to 5pm)
Email: whh-tr.fertilityunit-whitthealth@nhs.net