When a pregnant woman is diagnosed with cancer, her decisions are complicated by concern about how treatment may affect the baby’s health. Ideally, she can delay treatment until the baby is born, but sometimes a delay can allow the cancer to progress and make it harder to treat. The best time for beginning treatment to balance the baby’s and mother’s health needs isn’t always clear.
Cancer during pregnancy is rare, occurring in approximately one out of every 1,000 pregnancies, and little research is available to guide women and doctors. Breast cancer is the most common cancer in pregnant women; affecting approximately one in 3,500 pregnancies. The other common cancers in pregnancy are cervical cancer, lymphoma, and melanoma. A pregnant woman with cancer is capable of giving birth to a healthy baby, and some cancer treatments are safe during pregnancy. Cancer rarely affects the fetus directly.
If cancer is suspected during pregnancy, women may be concerned about diagnostic tests such as x-rays. However, research has shown that the level of radiation in diagnostic x-rays is too low to harm the fetus. When possible, women may use a lead shield that covers the abdomen for extra protection. Other diagnostic tests, such as magnetic resonance imaging (MRI), ultrasound, and biopsy, are also considered safe during pregnancy because they don’t use ionizing radiation.
Some diagnostic tests use liquid radioactive iodine to help stage cancer (figure out whether the cancer has spread to other parts of the body). Radioactive iodine cannot be used during pregnancy because it can damage or destroy the fetus’ thyroid gland.
When making treatment decisions for cancer during pregnancy, the doctor considers the best treatment options for the mother and the possible risks to the fetus.
The type of treatment given will depend on the following:
- The trimester of your pregnancy
- The type, location, size and stage of the cancer
- What the woman prefers
Because some cancer treatments can harm the fetus, especially during the first trimester (the first three months of pregnancy), treatment may be delayed until the second or third trimesters. When cancer is diagnosed later in pregnancy, doctors may wait to start treatment until after the baby is born, or they may consider inducing labor early.
Some cancer treatments may be used during pregnancy but only after careful consideration to optimize the safety of the mother and the unborn baby. These include surgery and chemotherapy. Radiation is generally not utilized during pregnancy. After evaluation your doctor will develop a treatment plan based on individual circumstances.
Read part 2.