Q: Do cancer treatments effect the fetus?

A: If the cancer is treated by surgery, the fetus will rarely if ever be affected unless there are complications of the surgey or anesthesia.

If chemotherapy is being used, the gestational age of the fetus will determine the effect. During the first trimester, fetal harm can occur as the organs are being developed. During the second and third trimester, chemotherapy can be used to fight off cancer without harming baby as long as a pregnancy safe chemotherapy drug is chosen.

Radiation will often be avoided during pregnancy. If the cancer will not respond to other treatments and the cancer is in an area other than the fetal area, radiation can be used.

Cancer treatments are often delayed during pregnancy for one of two reasons. Either the pregnancy symptoms intermingled with the cancer symptoms and the diagnosis was not made until later in the pregnancy or the cancer was detected early and the oncologist decided to wait until after the first trimester to begin treatment.

The most common form of cancer to affect pregnant women is breast cancer. About 1 out of every 3,000 pregnant women are diagnosed with breast cancer while pregnant. The treatment can be delayed, in most cases, until the second trimester. This gives the fetus enough time to successful form organs without the potential risks associated with cancer treatments.

After the first trimester, chemotherapy or surgery are often the best options for pregnant women. This is the case with all forms of cancer, not just breast cancer. If the cancer does not respond to the chemotherapy or surgery, the oncologist and obstetrician may choose to prescribe a medical course that could harm baby but could also save mom's life. The doctors will need to meet with the patient to weigh out the pros and cons of cancer treatments that may not be considered safe during pregnancy.