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BIG Time for Baby: Pregnancy after breast cancer

by BIG against breast cancer

After being successfully treated for breast cancer, Zoë dreams of having a baby


Why do we need this BIG Time for Baby study?

The majority of young women with early breast cancer have hormone-sensitive, or estrogen receptor-positive (ER+) disease, meaning the cancer cells are fed by their own hormones. 

To avoid the cancer returning, these women must follow 5-10 years of endocrine therapy, a hormonal treatment that impacts the ovaries and prevents conception.

About BIG Time for Baby

BIG Time for Baby is an international clinical study evaluating whether it is safe for women to interrupt their endocrine therapy to attempt pregnancy after breast cancer. Specifically, the study hopes to determine whether treatment can be paused for up to two years to allow for conception without increasing the risk of breast cancer recurrence.

The study will enroll up to 500 women with hormone-sensitive breast cancer to answer this important question.

It costs 21 euro per week (3 euro per day) per participant to carry out the study. Your donation will be used to cover the costs involved and ultimately provide solid answers to critical questions for future generations.

Where the money goes

This is a large international research effort coordinated by the International Breast Cancer Study Group (IBCSG) under the umbrella of the Breast International Group (BIG). All proceeds raised through this campaign will go to IBCSG and BIG to support the costs of the study.

500 patients are expected to be recruited to participate in this study worldwide. It costs 1080 euro per year per person to participate in the trial, with patients monitored for at least 10 years after enrolment. 

How the study works

Pre-menopausal women with hormone-sensitive early breast cancer who wish to conceive are eligible to apply to participate in the study through their doctor. Women should be between 18 and 42 years of age at the time of enrolment, and have already received endocrine therapy for 18 to 30 months.

After making sure the woman meets the scientific criteria of the study, and having confirmed their wish to participate in and understanding of the study, there are several steps, including:

Step 1: A three-month break in treatment before attempting conception

Step 2: Up to a two-year treatment pause to allow for potential conception, delivery and breastfeeding

Step 3: Treatment resumption and completion of full duration of endocrine therapy

If you are interested in a more detailed description of this important project, watch this video


The BIG Time for Baby study will give young women with hormone-sensitive breast cancer the opportunity to try for a baby.

The research associated with pregnancy after breast cancer is limited, making it challenging for a woman to navigate her fertility options.

The majority of young women with early breast cancer have hormone-sensitive, or estrogen receptor-positive (ER+) disease, meaning the cancer cells are fed by their own estrogens.  Endocrine therapy for patients with hormone-sensitive breast cancer may be prescribed for 5-10 years and impacts the ovaries, preventing conception while on treatment.  This is a dilemma for women who wish to conceive a child.

The BIG Time for Baby study, conducted by the International Breast Cancer Study Group (IBCSG), will answer these kinds of questions, which are so important to women with hormone-sensitive breast cancer who wish to try to conceive.

About the organisers

Breast International Group (BIG) ( is an international non-profit organisation that represents the largest global network of academic research groups dedicated to finding new ways to treat breast cancer and improve the lives of breast cancer patients.

The International Breast Cancer Study Group (IBCSG) ( is a Swiss non-profit co-operative breast cancer research organisation that has conducted clinical research in adjuvant endocrine therapy and chemotherapy, timing and duration of adjuvant therapies, and quality of life for over 35 years.

Can't spare a dime?

Even if you can't make a donation to support this project, please share our project through your social media channels.

- Tweet for BIG Time for Baby

Help @SupportBIG fund #BIGTimeforBaby to help women get pregnant after breast cancer 

- Share the campaign

Use the share tools at the side of the page (right side under 'I donate' to spread the word about the campaign to your network.

- Stay tuned

Follow BIG Time for Baby on Facebook for campaign updates and to share messages @SupportBIG


Robin Carney

250 €

Such a wonderful project - I m proud to be a part of it! Congratulations BIG against breast cancer!


Ana Sink

20 €


Tanja Spanic

50 €


34 €


Thierry Magerman

21 €

Très belle initiative. Bravo


Selma Djemail

10 €


Fedro Alessandro Peccatori

3 €

Be POSITIVE e In becco alla cicogna !


30 €


Akira Tsujimaru

21 €

Hello Petra, It was nice to meet you at the QA Conference in Nice! As promised my donation. Best Regards, Akira Tsujimaru MasterControl


100 €