LETROZOLE INDUCTION

If you’re contemplating ovulation induction through letrozole, to help get pregnant, it means your journey towards pregnancy hasn’t been an easy one. I’m sorry that you’ve had a hard journey and you’re having to think outside the box, but I do commend you on doing your research and having a look around.

Being unable to get pregnant is an extremely difficult, and often a very lonely path to walk. Thank you for choosing me to take this journey with you. I will do everything that I can to help you achieve your dream of motherhood.

This will NOT be for everyone, and to see whether you qualify, you will need an appointment (a long one) to go through whether this is even for you. Some women will be referred straight to IVF, a specialist fertility Gynecologist, or different fertility or recurrent miscarriage clinics. This will depend on your history, clinical examination, age and preference. Letrozole will NOT be prescribed day one. It will often be month 2-3 after starting your infertility journey so the sooner you come in the better. If you have PCOS and trouble getting regular periods, I usually tell patients to come in 12 months before they want to get pregnant so we can develop a plan on getting periods regular and getting ready to get pregnant.

What I want to do here, is give you some information on letrozole, so you understand WHY we’re doing this, WHAT we’re doing and give you some ideas of what to EXPECT. It’s the only agent I use for ovulation induction so I won’t go into the others.

What needs to be done first?

Before we start an induction program, you would have had general pre pregnancy bloods done, an AMH level (blood test which is sometimes called an ‘egg timer’ test) as well as a pelvic ultrasound and HyCoSy test (A ultrasound to check tubal patency ultrasound).
This way we can make sure that when we induce ovulation, the egg can travel down the fallopian tubes allowing you to get pregnant.

These tests need to be done at specific times so timing is important.

Blood tests to check for ovulation will also have occurred before one of your periods.

We would have seen that you’re not ovulating, your periods are very far apart, or we have diagnosed you have PCOS (or a combination of these).

Before starting letrozole, your partner will also have had a sperm analysis done also.

WHAT DOES LETROZOLE DO?

Letrozole works by stopping the conversion of androgens, or male like hormones, to oestrogens. The brain responds to this lack of oestrogen by releasing hormones which will the bring on ovulation.

This is often a medication used in menopausal women who have hormone dependent breast cancer as a way of reducing oestrogen and reducing the risk of cancers coming back.

We use it off label for ovulation induction.

It’s still going to be up to the sperm to reach the egg to fertilize it.

WHY LETROZOLE?

Letrozole is not for everyone. If you are ovulating but not getting pregnant, there’s no use trying a medication which has the sole purpose of bringing on ovulation.

Letrozole is first line for ovulation induction in women with PCOS, and it also has lower side effects that other agents, such as clomiphene which I do not use due to the risk of ovarian hyperstimulation (although still very low). Clomiphene also carriers a higher chance of twins (10-12%) compared to baseline, which is around 0.5%.

Letrozole carries a risk of around 5% of having twins (which is still up to 10x the rate in the general population).

RISKS / SIDE EFFECTS

The main risk of using letrozole is the risk of twins, which is under 5% (but is still higher than the general population which is 0.5%).

The risk of twins does carry a higher risk of complications for the pregnancy (see link below).

There is no risk, higher than baseline, for any foetal abnormalities using Letrozole.

The main risks for taking the medication itself, include headache, hot flushes, stomach upset, weakness, stomach pain, breast discomfort.

HOW DO YOU TAKE LETRZOLE

Letrzole is a tablet that you take for several days early on after a period.

The protocol will be discussed with you, once we decide to go ahead with this treatment.

HOW MANY CYCLES WILL WE DO

I am happy to do up to 3 cycles of letrozole with you, before I will refer you on to another specialist, such as a gynecologists who specialized in infertility, or an IVF doctor.

LINKS

Ovulation induction information

Multiple pregnancy risk