Fertility preservation in thyroid cancer

If you have recently been diagnosed with thyroid cancer, the first and most important advice is to keep calm! Thyroid cancer is the most common malignancy in women aged 15-30, and one of the most common after that.

Have no fear! WE BRING GOOD NEWS! Modern treatments involving surgical removal of part, or all of the thyroid gland and radioactive iodine therapy provide a cure for almost 100% of all newly diagnosed patients.

The thyroid gland produces two hormones (triiodothyronine and thyroxine) that are important for your metabolism and play a key role in normal egg development.

Surgical removal of the thyroid gland requires replacement medication, which patients take daily, but finding the dose you need can take months as adjustments are most often made 6-8 weeks apart.

In some cases, at the discretion of your oncologist, you may need to take supraphysiologic doses of thyroxine to suppress your hormone (thyroid-stimulating hormone, TSH).

As long as this therapy lasts, you will have a hyperthyroid condition in which getting pregnant is not recommended.

Treatment for the most common types of thyroid cancer (papillary and follicular) often involves post-operative management of the so-called radioactive iodine therapy. This is a treatment method, wherein the patient takes radioactive iodine (most commonly iodine-131) after surgery to completely destroy the small amount of cancer cells left in the body.

There is a waiting period of about 1 year before getting pregnant after radioactive iodine therapy.

In recent years, it has become clear that therapeutic doses of radioactive iodine result in a permanent decrease of anti-Müllerian hormone levels, which is the most accurate marker of ovarian reserve. 

In summary, therapy will cure you, that is certain, but treatment will badly affect your reproductive cells, and no one can say in advance whether that is reversible, as this is done on a case-by-case basis and depends on individual doses, duration, and characteristics of the organism.


This will give you peace of mind during treatment, it won't affect the carcinoma, it won't slow you down, and it is a quick procedure.

Frequently asked questions and common situations you may run into

Still, what if I decide not to freeze eggs?

Yes, that will be your decision to make; indeed, the chances of the ovary fully recovering after the iodine are not insignificant. If the ovary is permanently affected, you still have chance to get pregnant with donor eggs.

When is the most suitable time to freeze eggs?

Our experience shows that we get best results if this happens before the start of everything else, i.e., prior to surgery. That's when the TSH values are closest to physiological (and they affect egg quality). If post-surgery radioactive iodine therapy is planned, the team that treats you will, in all likelihood, recommend that TSH values should reach around 30 mIU/L (hypothyroid state), which will ensure the efficacy of the procedure, but this greatly hinders the egg maturation process.

However, if you are having surgery and reading these lines – relax! We are experienced in egg preservation after successful surgery, albeit a little late. We recommend that your stimulation be done immediately after surgery, because your TSH hormone levels will still be satisfactory.

What values of TSH are the best to freeze eggs?

Naturally at the physiological levels – up to 3, but if your hormone level is high, do not give up! We have experience with successfully frozen eggs with good quality TSH above 12. Just come in, we will make an assessment and we’ll make sure to discuss with your endocrinologist how much time you have until surgery and the options for adjustment. Do not give up if someone tries to talk you out of egg freezing because of the TSH values.

Is the specific histological type of cancer of importance?

Among 90-95% of all patients, this is a case of the so-called differentiated thyroid carcinomas (papillary or follicular with their subtypes). They are also the histological types with the best prognosis, and it is for them that radioiodine therapy is put into consideration, as they consist of cells that are similar to normal thyroid cells and, like them, absorb and use iodine in the body.

The medullar subtype occurs in about 5% of all cases and differs greatly in both its biology and treatment. Radioactive iodine therapy has no place in this treatment, and it is desirable to refer patients for genetic counseling, up to ¼ of all patients have a genetic mutation, which require caution for other malignancies.

Anaplastic thyroid carcinoma occurs in up to 2% of all cases, but predominantly affects patients aged > 65-70 years. It is also one of the most aggressive malignancies, but given its relatively low incidence, mostly in elderly patients, we will not dwell on it. If you are unsure of what comes next from your histological diagnosis, feel free to contact us, and we will discuss the next steps together.

What are my chances of getting pregnant after thyroid cancer?

As mentioned above, if action is not taken to preserve reproductive ability, the chances of a pregnancy occurring can decrease drastically. This is especially true for women aged over 35. Freezing eggs or embryos significantly increases your chances.


Remeber that...

You should seek advice NOW!

Every woman with thyroid cancer at reproductive age should consult a reproductive specialist, regardless of the stage of her disease and whether she has given birth or not.  This is also the official recommendation of the most reputable medical oncology and reproductive medicine organizations, such as ESMO, ASCO, and ESHRE.

This will not delay your therapy in any way.

Your consultation with our reproductive specialists will be provided within 24 hours of your call, no matter where you are in the country. If you choose to preserve your fertility we can begin immediately, regardless of your menstrual cycle date, and the process will be completed in about 10 days.  There is an exceptional coordination between the reproductive specialists and medical oncologists in our hospital, allowing the planned treatment to begin immediately after successful egg retrieval.

The procedure has been proven safe and in no way worsens the prognosis for the cancer. If previously discussed and coordinated with the treating medical oncologist a possible subsequent pregnancy is proven to be safe.


Fertility preservation options 

In current practice, the following approach is used to preserve reproductive ability among patients with thyroid cancer:

Fertility preservation options

Frequency of application and success rate of the approach

Egg/ embryo freezing ★★★ 

★★★ - most commonly used approach, highest success rate ★★ - less frequently used approach, lower success rate - rarely used approach

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