Cancer Care Pregnancy Women's Health

5 FAQ’s About Breast Cancer Risk and Pregnancy

Approximately one in eight women living in the U.S. will receive a breast cancer diagnosis during her life. Breast cancer and pregnancy have a significant impact on one another, and women who currently have or have had breast cancer need to understand the relationship and risks before deciding to become pregnant.

Stephen Frausto, FACOG, MD, a Steward Health Care physician who specializes in obstetrics and gynecology, answers some frequently asked questions on the topic.

Q. Does pregnancy affect breast cancer risk?

A. There is a complex relationship between breast cancer and pregnancy. Significant hormonal changes occur throughout pregnancy, and these affect the breast. During pregnancy, a woman is considered to be “progesterone dominant” meaning the progesterone levels are higher and estrogen levels are lower. Progesterone isn’t the “bad” hormone in breast cancer development.

Breast cancer risk is also linked to the timing of a woman’s pregnancy. The earlier a woman gets pregnant in her life reduces the risk of breast cancer. If she waits to have her first child and is over the age of 35, it can slightly increase risk.

Q. How is breast cancer treated during pregnancy?

A. Treatment depends on the stage of the breast cancer diagnosed and the stage of pregnancy. If a woman is full-term at diagnosis, her health care team may decide to induce or schedule a c-section to begin treatment.

Q. Can breast cancer treatment affect getting pregnant?

A. Yes, it certainly can. Young women who are treated for breast cancer with chemotherapy may experience decreased fertility rates and be less likely to become pregnant, due to chemotherapy-related damage to the ovaries. Additionally, early menopause may be brought on by chemotherapy.

Q. Are there risks getting pregnant after having breast cancer?

A. If a woman is on hormone therapies, such as Tamoxifen (an anti-estrogen drug) getting pregnant should be avoided as these types of drugs are harmful to the fetus.

Q. What happens with breast cancer risk and pregnancy after age 40?

A. A woman’s breast cancer risk increases after age 40. For many females, 40 or older, the fertility rate is decreasing, and the breast cancer rate is increasing. If a woman has had multiple pregnancies before age 40, she is at less risk than the woman who is having her first child over age 40.

Catch it early!

Early detection of breast cancer is critical and regular breast examinations throughout a woman’s life are vital in the early detection. Beginning at age 20, women should begin performing self-exams. If you are pregnant, your OB-GYN should examine your breasts early in the pregnancy, as the breasts quickly become very dense and difficult to examine. Breast examinations should be repeated after delivery. And for older woman, the American Cancer Society recommends annual mammograms beginning at age 40.

Be vigilant. If you have any questions or concerns about your breast cancer risk, talk to your physician.

To find a doctor or schedule an appointment, visit Steward DoctorFinder™.

*Source: American Cancer Society,