For years, many believed that having had breast cancer ruled out pregnancy. You may have heard that pregnancy speeds up the spread of breast cancer or causes recurrences.

Today, most breast cancer specialists agree that pregnancy doesn’t increase your risk for getting breast cancer. And it doesn’t cause breast cancer to return after treatment. There’s even evidence that pregnancy may provide some protection against breast cancer.

Estrogen and breast cancer

Estrogen is essential to pregnancy. It’s important for the development of your baby’s organs, and aids in the increase of blood flow and expansion of your uterus. Estrogen also has a key role in milk production.

Estrogen is also associated with breast cancer. Both normal cells and cancer cells contain protein molecules called estrogen receptors. When estrogen circulates in your body, it attaches to cells that have estrogen receptors. This can cause cancer cells to divide and spread.

How long should I wait?

Getting pregnant after breast cancer is possible, and you can go on to have a healthy pregnancy and baby. For most women, cancer treatment, not pregnancy, is the main safety concern.

Experts differ in their opinions about how long you should wait to become pregnant after completing cancer treatment. Some doctors say it’s a good idea to wait two years after treatment because recurrences are less likely to occur after this point. It’s widely recommended that you wait at least two months after discontinuing tamoxifen before becoming pregnant. Tamoxifen is a hormone therapy that may harm your fetus if taken during pregnancy.

It’s best to talk with your doctors about how long you should wait before getting pregnant. Your health status is the most important consideration.

Will breast cancer affect fertility?

In most cases, cancer treatment will shorten the window of time in which you are fertile. Many women undergoing chemotherapy stop having their periods. For some, this signals premature menopause, or chemotherapy-induced menopause. Periods often start again after completing treatment, especially in women under age 35.

Factors that influence fertility are:

  • your age
  • the type of drugs used in your treatment
  • the doses of drugs used
  • if you’ve had radiation treatment

Breast cancer treatment can pose a risk to fertility. So, you may want to take steps to safeguard pregnancy in the future:

  • Have your eggs harvested and stored for later use.
  • Embryos, or eggs fertilized via in vitro fertilization, can be more viable than unfertilized eggs. After your treatment is complete, embryos can be implanted.
  • Suppress your ovaries with medication or surgery.
  • Ovarian tissue freezing, still considered experimental, involves surgically removing parts of the ovaries containing eggs and hormone-producing cells. The tissue is transplanted back into your uterus at a later date.

Will I be able to breastfeed?

You may be able to breastfeed after you’ve had a lumpectomy. This depends on the amount of breast tissue removed and the condition of the remaining tissue. You can also breastfeed from the other breast if it wasn’t affected by cancer.

If you aren’t able to breastfeed, formula also provides the nutrition your baby needs. Hold your baby close when feeding from a bottle. Consider unbuttoning your shirt for skin-on-skin contact.

Talking to your doctor

Talk with your doctor before starting treatment if you want to have children in the future. They can help you understand your options.

  • Ask how long you should wait before becoming pregnant after treatment ends.
  • If your doctor prescribes tamoxifen, ask how long you will take it.
  • Discuss what form of birth control you should use. You shouldn’t use hormonal birth control, like birth control pills when you have breast cancer.
  • Consider talking with a fertility specialist and your oncologist if you want to become pregnant in the future.


It’s generally agreed that pregnancy is safe if you’ve had breast cancer. In fact, pregnancy may offer some protection against breast cancer. Always talk with your doctor about your concerns. You’ll get important information.