Being diagnosed with cancer is one of the most stressful things you could ever experience, and being diagnosed while pregnant can be overwhelming. At the same time that you are hoping to bring a new life into being, you are also in a fight to protect your own life. You may be worried that the treatment might harm your baby or you may be concerned that it won’t be effective enough.
Cancer during pregnancy is uncommon, occurring in only 1 in every 1000 pregnancies; however, in recent years the incidence has been increasing, and this is more than likely due to women deciding to have children later in life which is when cancer also tends to develop.
The most common cancers that occur during pregnancy include:
- Cervical cancer
- Breast cancer
- Thyroid cancer
- Hodgkin lymphoma
- Non-Hodgkin lymphoma
- Melanoma
- Gestational trophoblastic tumor
Diagnosing cancer during pregnancy
Unfortunately, a cancer diagnosis can be delayed if a woman is pregnant. This is due to the cancer symptoms being similar to pregnancy symptoms, and therefore not raising alarm bells. These symptoms include the following:
- Fatigue
- Rectal/vaginal bleeding
- Breast changes
- Bloating
- Headaches
In some cases, however, pregnancy can uncover cancer when routine tests are carried out, such as a cervical smear or an ultrasound of the ovaries.
There are several types of diagnostic tests that are performed when a doctor suspects that a patient may have cancer.
- X-rays: Studies have shown that the levels of radiation used in X-rays for diagnosing cancer are too low to affect the fetus. However, to be on the safe side, a lead blanket which shields the abdomen from radiation is used whenever possible.
- Computed tomography (CT) scan: CT scans of the head and chest are generally safe during pregnancy because the fetus is not directly exposed to the radiation. However, CT scans of the pelvis or abdomen should only be done if absolutely necessary and when possible a lead blanket should be used to shield the fetus from the radiation.
- Magnetic resonance imaging: Generally safe during pregnancy as it doesn’t use ionizing radiation.
- Ultrasound: Generally safe during pregnancy as it doesn’t use ionizing radiation.
- Biopsy: Generally safe during pregnancy as it usually involves taking a small sample of tissue.
Cancer during pregnancy is uncommon, occurring in only 1 in every 1000 pregnancies; however, in recent years the incidence has been increasing, and this is more than likely due to women deciding to have children later in life which is when cancer also tends to develop.
Treatment for cancer during pregnancy
Before you start treatment your obstetrician will carefully determine the age of the fetus, the maturity of the fetus, and estimated due date. The treatment options are the same for a non-pregnant woman, but the schedule may need to be adjusted with respect to how and when the drugs are administered. The type of treatment and when it is given depends on several factors:
- The type of cancer
- The location of the cancer
- How advanced the cancer is
- How advanced the pregnancy is
- The preferences of the mother
In general and depending on the type of cancer, surgery is the preferred initial treatment for a woman who is pregnant as it poses the least risk to the fetus. General anesthesia is usually quite safe for the fetus.
In the past, women used to be advised to give birth to their babies before embarking on chemotherapy for the cancer due to doctors being worried that the fetus would be harmed. This was due to there being almost no information about how babies with in utero exposure turned out. Currently there is a lot more information about this, and we know that it is relatively safe for the baby to be exposed to chemotherapy after the first trimester. The placenta acts like a barrier between the mother’s blood and the fetus and consequently many chemotherapy drugs are unable to reach the fetus. One study followed children up to 18.5 years of age who had been exposed to chemotherapy in the second and third trimesters, and found no issues with their fertility, nervous systems, or psychological state.However, other studies have found that chemotherapy during this period is associated with early labor and low birth weight. In addition, some of the side effects of chemotherapy, such as anemia, infection, nausea and vomiting can harm the fetus.Chemotherapy will usually be stopped after 35 weeks and following the birth, the baby may have a low white blood cell count. Some types of chemotherapy are not suitable at all during pregnancy – these include hormonal treatments (for breast cancer) and some targeted treatments such as Herceptin (also used for breast cancer).
Radiation is not recommended during the first trimester but depending on the dose required and location of the tumor, it may be used in the second and third trimesters. When the tumor is far away from the abdomen, such as head and neck cancer or breast cancer, careful planning is needed to prevent the fetus from being exposed to radiation. If the woman has a tumor in the pelvic area, radiation therapy is not possible due to the risk of severe side effects for the fetus, such as malformed organs, small brain, stunted growth, and developmental delays.
