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What to Know About Pregnancy After Cancer

For survivors who are starting or expanding their families, choices can be difficult and fears almost guaranteed. Here are the facts, straight from a Harvard expert.

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Congratulations! You've made it though breast cancer and are ready to build your family. There might be a lot of questions and concerns swimming through your head: 80 percent of breast cancers are fueled by hormones—how will a pregnancy affect your cancer returning? Can you even get pregnant at all after treatments?

We asked Ann Partridge, MD, MPH, Breast Cancer Research Foundation Investigator, professor of medicine at Harvard Medical School and director of the Adult Survivorship Program at the Dana-Farber Cancer Institute in Boston, to weigh in—now those are some impressive credentials.

Pregnancy is safe, but could be difficult

First, the good news: Doctors are generally on board with your efforts to have a baby. "The most recent data does not suggest that pregnancy increases or decreases risk of a breast cancer recurrence," Dr. Partridge says. "We generally support women to become pregnant after a breast cancer, understanding that just because a pregnancy does not increase risk of breast cancer recurrence, it can and sometimes does happen regardless in survivorship." Your doctor might advise you to wait two to three years to get pregnant after a diagnosis, because that's the highest period of recurrence.

Even then, getting pregnant might not be as easy as you hoped. Freezing your eggs or embryos before starting treatment can avoid the ovary-zapping effects of treatment. "Chemotherapy can directly damage cells in the ovaries which can impair fertility," Dr. Partridge says. But the aggressiveness of the disease may not give you the time to hold off on treatment to freeze your eggs.

And some cancers are treated with hormonal therapies, which are toxic to a fetus. Pregnancy is not recommended during treatment—which is a whopping five to ten years long. "Hormonal therapy is not directly damaging to fertility, but ovaries are aging during that time which can decrease fertility," Dr. Partridge says. "Some women will elect to not take a full course of endocrine therapy, and come off early or interrupt in order to have a pregnancy." An ongoing clinical trial testing this interruption strategy in young women with early breast cancer may help women decide if this is a good strategy for them.

Wishing for a healthy baby

Breast cancer survivors may also be concerned about their ability to breastfeed, which will largely depend on their individual case. "Women who have a baby after breast cancer can breastfeed from the unaffected side and sometimes from the side that was affected if the breast remains, although surgery and radiation often result in low yield of milk from that breast," Dr. Partridge says. Breastfeeding lowers cancer risk in general, and women with a history of breastfeeding who do get cancer have a lower incidence of recurrence.

Survivors may also be concerned about passing down genes linked to breast cancer to their children. "Some parents who know they have a change in a cancer-related gene that increases risk will elect to have in vitro fertilization [IVF] and have those fertilized eggs checked for the genetic change, and only the embryos that don't have the particular change will be used," Dr. Partridge says.

But in general, women who've had breast cancer can go on to have safe pregnancies and healthy children. "A mother's history of breast cancer should not affect the development of a subsequent baby," Dr. Partridge says.