Leaflet Details
| Title | Ovulation Induction with Letrozole Treatment |
| Department | Gynaecology |
| Author(s) | Dr Megan Carr and Miss Lilian Ugwumadu |
| Review Date | January 2023 |
| Next Review | January 2027 |
| Download | A5 Booklet PDF |
| Accessibility Options | Click on the Recite Me button to show our accessibility resources |
Patient Information
Introduction
This information leaflet is for women undergoing fertility treatment who has been prescribed Letrozole tablets.
What is Letrozole and why is it prescribed?
Letrozole belongs to a class of drugs called aromatase inhibitors and it is a fertility drug to stimulate ovulation. Letrozole works by lowering the oestrogen levels which in turn increases the hormone FSH which causes the ovaries to develop a follicle with an egg inside.
When is it prescribed?
- if you are not ovulating
- if you have not responded to or tolerating clomiphene
- if treatment with clomid has negatively affected the lining of your womb previously (thinned the lining)
How should this medicine be used?
- Letrozole is a tablet taken by mouth.
- Letrozole tablets are given for five days, beginning on the second full day of your period (day one is the first full day of bleeding).
- To help you remember, take the tablet around the same time every day.
What if you have no menstrual cycle?
If you are having very irregular periods or no periods, you will be asked to take progestin (such as Provera) to bring on a period. Then commence the Letrozole on the second day after your induced period has started.
When is the optimal time to have intercourse?
The best time to have intercourse is from 5 days after the last Clomid tablet (day 10 in the cycle) every other day for one week; although it is recommended, when trying to achieve a pregnancy, to have regular sexual intercourse 2-3 times per week.
How is the response to treatment monitored?
It is important to confirm that an egg is being produced in response to the treatment and also that you are not producing too many eggs. This will mean having a vaginal ultrasound scan around day 10 of your menstrual cycle. The follicle number, size and rate of growth as well as the endometrial thickness are studied by ultrasound. You will also have a blood test (progesterone levels) a week after positive ovulation (around day 21) to confirm.
- If you are responding to the Letrozole, there is no need for further monitoring.
- If you ovulate but do not conceive and menstruation occurs, the same dose of Letrozole is repeated in the following cycles.
- If you are not responding after, then the dose of Letrozole will be increased, and you will be monitored for the following cycle.
Do not increase the dose yourself.
As there is a risk of producing too many eggs you should not have unprotected sexual intercourse on your first treatment cycle prior to this scan.
The treatment is for a maximum of 6 cycles. We may decide to shorten the treatment depending on how you respond to the medication.
What should I do if I forget a dose?
Take the missed dose as soon as you remember. However, if it is almost time for the next dose, email or call the fertility unit for additional instructions. Do not take a double dose to make up for a missed one.
What side effects can this medication cause?
Whilst taking the Letrozole tablets, you may experience some mild side effects that include hot flushes, nausea, headaches, dizziness or blurred vision (uncommon). Rarely abdominal discomfort may occur if your ovaries have over-responded to the Letrozole (ovarian hyper-stimulation syndrome - OHSS). If this occurs, please contact your GP or the fertility unit for advice.
In the normal menstrual cycle, only one egg develops each month. Letrozole may cause more than one egg to mature and this increases the risk of multiple pregnancies to about 1 in 10. The rate of miscarriage is not increased, nor is the incidence of congenital anomalies.
To book your ultrasound scans:
Please contact the Fertility unit on the first day of your period to book your scan (if your period starts on a weekend, then email or telephone on the Monday). Please note scanning is not available at the weekend.
Further advice
- Take Folic acid 400mcg daily to reduce the risk of spina bifida in the baby you do conceive.
- Vitamin D supplements.
- Maintain a normal weight and continue to lose weight if you are overweight.
- Not to smoke.
If you have any further questions please contact:
Fertility Unit
Email:
01923 723973
