By Dr. Elisa Pérez (Gynaecologist – Reg. No. 203311163).
When a woman is diagnosed with breast cancer, she will probably not think about her future fertility, as the fear of this disease and how it will evolve will occupy all her thoughts.
However, it is very important to be clear about whether we would like to have the option of becoming mothers once the treatment is over, as the effects of chemotherapy can be devastating for our reproductive capacity. Oocyte cryopreservation plays a key role here and can help women overcoming cancer to achieve pregnancy.
According to the Observatorio del Cáncer of the la Asociación Española Contra el Cáncer, 34740 people were diagnosed with breast cancer in Spain in 2022, mainly women. In fact, it is the most common cancer among Spanish women and the most common cancer worldwide, and it is estimated that up to 1 in 8 women will suffer from it in their lifetime.
The survival rate, however, is over 85% within 5 years of overcoming it, although it can have negative effects on women's fertility. Chemotherapy or pelvic radiotherapy treatments can damage the ovaries and reduce the number of oocytes, so it is advisable to consult a specialist about the possibility of freezing oocytes before starting treatment.
X-ray of a woman with breast cancer
It depends on many factors, but pregnancy is possible. The first step is to undergo a medical evaluation in which a specialist can check your health and your ovarian function after treatment. In addition, it is advisable to wait for a period of time after finishing the cancer treatment and starting to get pregnant, usually around two years, which is the time to monitor a possible reappearance of the cancer and to ensure that the body has recovered properly.
It should be noted that not all women who undergo this type of treatment suffer permanent infertility. In fact, it is estimated that the rate of recovery of ovarian function can be between 20% and 70% depending on the type of chemotherapy used to fight the cancer. If a natural pregnancy is not possible, there are different assisted reproduction methods that can help the process, such as in vitro fertilisation (IVF), oocyte donation or embryo adoption.
Immediately after the diagnosis of cancer and before starting chemotherapy treatment, the possibility of preserving fertility through oocyte vitrification should be considered. It is a technique in which oocytes are retrieved before they can be damaged by the treatment and preserved for use once the disease is overcome. According to data from the Sociedad Española de Fertilidad (SEF), almost 40% of oocyte vitrification cycles during 2021 were due to medical reasons.
The rest were for social reasons. It is a safe technique that is highly effective in women who have decided to postpone the moment of becoming mothers and want to do so with their own oocytes, avoiding oocyte donation.

Whether gestation is natural or through assisted reproduction, pregnancy after breast cancer is safe for both mother and baby. Moreover, current data indicate that pregnancy does not increase the risk of breast cancer recurrence, although it is important to have a complete evaluation with the oncologist before becoming pregnant and an adequate medical follow-up during pregnancy to confirm that everything is progressing perfectly.
Dr. Elisa Pérez, gynecologist, medical director of IVF-Life Donostia and expert in human reproduction.