Most Women Can Become Pregnant After Breast Cancer Treatment

Key Points:

• In this study, 73% of approximately 200 women who reported trying to become pregnant after breast cancer treatment succeeded, and 65% gave birth.
• Of the women, 28% underwent fertility preservation procedures to freeze eggs or embryos shortly after their breast cancer diagnosis.
• The interval from diagnosis to the first pregnancy ranged from six months to almost 10 years.
• Women who froze eggs or embryos were more likely to give birth than those who did not.

After nonmetastatic breast cancer, most young women who try to become pregnant after treatment succeed.

ASCO 2024 Congress pre-meeting findings on women diagnosed with breast cancer before age 40 represent the most comprehensive review of fertility outcomes after treatment (Abstract 1518).

Dr. Kimia Sorouri, a research fellow at Dana-Farber Cancer Institute, and colleagues examined data from 1213 women in the United States and Canada diagnosed with stage 0-III breast cancer between 2006-2016. None had metastatic disease at diagnosis or had previously undergone hysterectomy (removal of the uterus) or oophorectomy (removal of the ovaries).

During a median follow-up of 11 years, 197 women attempted pregnancy. Of these, 73 percent reported becoming pregnant and 65 percent reported a live birth at a median of 4 years after cancer diagnosis. Their median age at diagnosis was 32, and 28 percent chose egg or embryo freezing to preserve fertility. Notably, 68 percent received chemotherapy that could impair fertility, and only a small proportion underwent ovarian suppression during chemotherapy.

Main Predictors of Pregnancy or Live Birth 

The study identified the following main predictors of pregnancy or live birth:

• Financial Comfort: This self-reported measure was defined as having money left after paying bills. Financial comfort was an important predictor of pregnancy or live birth. Financially comfortable women were 2 times more likely to become pregnant or have a live birth (odds ratio [OR] 2.04; 95 percent confidence interval [CI] 1.01-4.12; P = 0.047).

• Younger Age at Diagnosis and Fertility Preservation: Younger age at diagnosis and fertility preservation procedures were other predictors of pregnancy or live birth. Women with younger age and fertility preservation interventions were 2.8 times more likely to become pregnant or have a live birth (OR 2.78; 95 percent CI 1.29-6.00; P = 0.009).

• Chemotherapy and Other Treatment Factors: These were not associated with pregnancy or birth outcomes.

In this modern era of greater fertility awareness, increased access to fertility preservation helps mitigate some of the damage caused by chemotherapy and other agents. This highlights the need to expand access to fertility preservation services for women diagnosed with breast cancer who want to become pregnant in the future.

Changing Attitudes Over the Past 20 Years

In this modern era of greater fertility awareness, access to fertility preservation may help mitigate some damage caused by chemotherapy and other agents. This highlights the need to expand access to these services for women diagnosed with breast cancer who want to become pregnant in the future.

These findings reflect a change unfolding over decades. Twenty years ago, this patient group was told, "You cannot become pregnant. It is too dangerous. You will not be able to." Some indeed cannot, but most who try succeed, particularly if they preserve eggs or embryos. Even if chemotherapy causes menopause or reduces fertility, preserving eggs or embryos now allows us to mitigate a distressing effect experienced by many patients in the past. That is the good news.

These positive results apply only to women who attempted pregnancy. There are also patients who entered menopause, did not freeze eggs or embryos, or do not want to become pregnant. Insurance may also decline to cover in vitro fertilization for women who have had breast cancer.

The association between financial comfort and reproductive success points to access problems in fertility preservation. But this is not only about insurance coverage. The oncologist should discuss the issue and inform the patient. Such information must be delivered appropriately at critical times, such as diagnosis, when patients may be least psychologically ready to hear it.