What to know about having children after a breast cancer diagnosis

The number of women diagnosed with breast cancer annually is growing, and many women are also waiting longer to have children.

For people who are undergoing or have undergone treatment for breast cancer – especially chemotherapy – there are many factors to consider when trying to become pregnant, including how long it has been since completing treatment.

We asked Stacie Heuer, PA-C, who sees patients with breast cancer at the M Health Fairview Cancer Center – Edina, what you should know about fertility and pregnancy after a breast cancer diagnosis.

What are the potential effects of breast cancer treatment on fertility?

Many young breast cancer patients will undergo chemotherapy, which can affect fertility by harming the ovarian tissue or damaging eggs.

This damage can cause either a temporary or permanent lack of periods and ovulation, but most women will start getting their periods and ovulating again after treatment. The younger a patient is, the more likely their ovarian function is to return. The closer to menopause, the more likely it is that the patient will remain without menstrual cycles.

Restarting menstruation and ovulation can take up to one year to occur. After treatment, there will be less ovarian tissue and eggs, which means women will be closer to menopause. If periods and fertility don’t return, they may have entered early menopause due to treatment.

The treatment agents most known to cause this damage include Cytoxan and platinum-based drugs such as carboplatin. Taxol or other taxanes such as Abraxane are relatively new, and there is limited data on their effect on fertility.

Can breast cancer treatment affect pregnancy and childbirth for women who return to fertility?

During chemotherapy treatment and for six months after, pregnancy is not advised even if the patient is having periods because damage to the eggs can increase the risk for birth defects. The damaged eggs will slowly die off in the months after finishing chemotherapy.

For young women who return to fertility, most data show they are as likely to conceive as women who have not had breast cancer treatment, and there doesn’t appear to be an increased risk for birth defects. There may be an increased risk of pregnancy complications such as preterm delivery, low birth weight, or the need for C-section.

Additionally, studies have shown that a post-treatment pregnancy does not increase the risk of cancer recurring.

Are there ways to limit the effects of chemotherapy on fertility?

In order to protect ovarian function from the effects of chemotherapy, and to increase the likelihood that the patient will resume normal periods and regain fertility, pre-menopausal women should receive a medication to temporarily slow ovarian function. This is known as ovarian suppression.

Ovary suppressing medications are often given in hormone receptor positive breast cancer as part of treatment. They’re an additional way to minimize estrogen, regardless of the patient’s desire to preserve fertility. While the ovary function is suppressed (either from ovarian suppression or from chemotherapy, itself) patients may experience menopausal symptoms such as hot flashes.

In addition to ovarian suppression, certain patients are able to undergo egg or embryo freezing as a way to preserve fertility, though these procedures can delay treatment.

What about people undergoing other therapies for breast cancer?

A recent clinical trial showed that pausing endocrine therapy after surgery may be safe in early-stage breast cancer that is hormone receptor positive. Early results of the trial show that after taking endocrine therapy for at least 18 months, a pause for up to two years did not lead to an increase in cancer recurrence compared to patients who continued the therapy. Additionally, patients who did pause endocrine therapy had similar conception and birth rates to the general population.

Some of the patients in this study also underwent chemotherapy, and most had some form of breast surgery. The study is ongoing and we’re hopeful to gain more information, such as if this can be applied for multiple pregnancies and if there’s an increased risk of pregnancy complications for these women.

What else should people know about becoming pregnant after breast cancer treatment?

No matter what the person’s breast cancer treatment will be, it’s important to talk to their oncologist about fertility concerns prior to starting treatment.

For people who have had breast cancer treatment and are experiencing infertility, we recommend seeking fertility counseling sooner than the average patient, within one year of trying to become pregnant without success.

To schedule an appointment with our team of breast cancer specialists, call 855-486-7226.