Cancer during pregnancy
On rare occasions, cancer coincides with pregnancy. Because the medications and radiation used for treating cancer can be dangerous to a fetus, a pregnant woman and her doctors must weigh a number of factors when planning her care, including:
- The fetus's gestational age.
- The type and location of the cancer.
- How advanced the cancer is.
- How rapidly the cancer is developing.
- Whether she has other health problems.
In nonpregnant people, surgery may be used to remove cancer, depending on the cancer's type and location. After surgery to remove cancer, radiation, chemotherapy, or a combination of the two may be used to kill any remaining cancer cells. When treating a pregnant woman, doctors adjust the usual treatment regimen with the following in mind.1
- Radiation is not used for therapy during pregnancy because it increases the risks of fetal death, birth defects, and low birth weight. Therapeutic radiation during pregnancy also increases the risk of cancer later in the child's life. Diagnostic tests that use radiation may be used during pregnancy if necessary. But ultrasound and magnetic resonance imaging (MRI) are considered safer and are used whenever possible.
- Chemotherapy is not used during the first trimester because of significant risks of fetal death or malformation.
- Some types of chemotherapy can be used after the first trimester, when the fetus is fully developed and malformation risk is past. However, chemotherapy medication does cross the placenta and can be toxic to a fetus. Chemotherapy used any time during pregnancy can cause low birth weight. It may also cause miscarriage or premature birth.
Whenever possible, doctors try to delay chemotherapy during pregnancy to minimize the effects on the fetus. Such decisions depend on how advanced the cancer is and how quickly it is developing.
- If cancer is diagnosed in the third trimester, it may be possible to first deliver the baby, then start treatment. Once the fetus's lungs are mature, as confirmed by amniocentesis, an early cesarean or induced delivery can shorten the wait till treatment.
- If cancer is diagnosed in the first or second trimester, your doctors may try to delay chemotherapy as long into the second trimester as possible.
- If advanced cancer is diagnosed in the first trimester, and immediate radiation and chemotherapy are necessary, your doctor may recommend ending the pregnancy.
If you have been diagnosed with cancer during your pregnancy, you will be working with a number of health professionals. Ask your cancer specialist (oncologist) for the name of a licensed medical social worker who can help support you through your treatment. A social worker can also help coordinate the various professionals involved with your care.
Last Updated: November 28, 2008