Because each woman is different, no one can know for certain how your cancer treatment will affect your chances of having a baby. Chemotherapy drugs used to treat breast cancer can affect your fertility, either temporarily or permanently. The drugs can damage your ovaries, which store your eggs. Your body only has a certain amount of eggs, so damaged eggs cannot be replaced or restored. Chemotherapy can also affect the body’s production of the hormones needed to become pregnant. For this reason, many women who need chemotherapy often take steps to preserve their fertility so they can become pregnant in the future.

Preserving Your Fertility

How much your fertility is at risk from chemotherapy depends on your age, whether you had fertility problems before treatment, and the type of medication you receive. Certain chemotherapy drugs used to treat breast cancer are more likely than others to cause fertility problems. These include Carboplatin, Cytoxan, and Doxil.

A fertility specialist can perform tests to find out your chances of becoming pregnant. This usually includes a physical exam and blood test. Women who wish to preserve their fertility while they undergo chemotherapy have a few options:

Embryo cryopreservation. The most successful way to preserve fertility is by fertilizing and then freezing your eggs. After taking fertility drugs for about two weeks, your eggs are collected and fertilized with your partner or donor’s sperm in a laboratory. The embryos are then frozen until you’re ready to become pregnant.

Oocyte (egg) cryopreservation. After the eggs are collected, they’re frozen unfertilized and stored until you’re ready to become pregnant. Egg freezing is typically less successful than embryo freezing, but many young women choose this option if they don’t have a partner.

Ovarian suppression. A drug known as goserelin (Zoladex) is given to temporarily stop the ovaries from working while you’re having chemotherapy. This lowers the chances of ovarian failure later. According to a recent study, women who took goserelin with chemotherapy for early-stage breast cancer were 64 percent less likely to have ovarian failure.

Ovarian tissue cryopreservation. While the procedure is still considered experimental, ovarian tissue cryopreservation is another option to freeze all or part of your ovary. When you’re ready to have children, the ovary tissue is transplanted back into the body and starts to produce eggs and hormones again.

Once your fertility specialist explains your options, you may want to ask how much the fertilization preservation costs and if the procedure will be covered by your health insurance. You may also want to ask about any expected delays in starting treatment if you choose one of these options.

After Chemotherapy Ends

Some oncologists suggest that women avoid getting pregnant within the first six months after chemotherapy sessions end. This gives time for any eggs that may have been damaged by the chemotherapy drugs to leave the body. Other oncologists think it’s a good idea to wait at least two to five years. If the cancer returns, it usually happens within this period. If you’re pregnant when the cancer returns, your options for cancer treatment may be limited.

You may be recommended to take certain pills that suppress the needed hormones for pregnancy to prevent the cancer from coming back for several years after chemotherapy is complete. While on this pill, pregnancy isn’t advised.

If you’re having problems getting pregnant after the waiting period ends, a fertility doctor can help again with other procedures to increase your chances.

What if You’re Pregnant Now?

According to the American Cancer Society, 1 out of 3,000 pregnant women will be diagnosed with breast cancer. It’s not yet known how chemotherapy drugs affect the fetus if treatment is done during the first trimester of pregnancy. But several research studies have shown that taking certain chemotherapy drugs during your second and third trimesters doesn’t increase the chances of your baby being born with a birth defect.

After the baby is born, it’s recommended that mothers not breastfeed during chemotherapy. Many chemotherapy drugs can be passed through breast milk to the baby.

Even if you aren’t sure if you want to have children, talk to your oncologist about your fertility. Ask if it’s safe to delay your chemotherapy until you explore your fertility options. Also, ask for a referral to a fertility specialist who will help you better understand ways to preserve your fertility.