Receiving a cancer diagnosis during pregnancy can be frightening. The excitement of pregnancy may quickly be replaced by the fear of cancer. Soon after, a mother’s focus usually shifts to a strong desire to protect her unborn child at all costs. Pregnant women with cancer often stop focusing primarily on the cancer itself and instead concentrate on recovery for the sake of their unborn baby, their other children, their partner, or other family members who may need them.
Pregnant women experience cancer differently compared with non-pregnant women. On the one hand, they are confronted with the serious impact of not only having to fight for their own lives after a new diagnosis, but also worrying about how their life-saving treatment might affect another life growing inside them. A more positive difference is that once treatment decisions are made and the initial shock of the diagnosis has passed, many women realize that at the end of this treatment a baby will be born—something to look forward to in a way that is unlike most “rewards” at the end of standard cancer treatment.
Breast cancer is the most frequently diagnosed cancer in pregnancy. In fact, approximately 7% to 10% of women diagnosed with breast cancer are younger than 40 years. When cancer is diagnosed in women aged 30 and younger, it is estimated that 10% to 20% of these cancers occur either during pregnancy or within the first year after delivery. Melanoma, Hodgkin and non-Hodgkin lymphoma, cervical cancer, and many other systemic cancers can also be diagnosed during pregnancy. Among these, only melanoma and lung cancer have the potential to metastasize to the placenta.
As women delay both marriage and childbearing for career and other reasons, the average age of a woman at her first pregnancy is now higher than in previous generations. This shift may help explain the increasing number of cases in which various types of cancer are diagnosed during pregnancy. Because the experience of diagnosing and treating cancer in pregnancy is relatively rare, it is difficult for healthcare systems at every level to accumulate enough cases to clearly determine the safest way to treat cancer during pregnancy.
How Is Cancer Diagnosed During Pregnancy?
Detecting cancer in a pregnant woman can be more difficult. This is because some cancer symptoms—such as bloating, headaches, or rectal bleeding—are also relatively common during pregnancy in general. The breasts typically enlarge and the tissue changes during pregnancy, and these breast changes may appear normal. As a result, cancer-related breast changes may be noticed later in pregnant women, and therefore cancer may be diagnosed at a more advanced stage compared with non-pregnant women.
Sometimes pregnancy itself can lead to the discovery of cancer. For example, a Pap smear performed as part of routine prenatal care may detect cervical cancer, or an ultrasound performed during pregnancy may reveal an ovarian tumor.
Some of the tests doctors use to diagnose cancer are considered safe during pregnancy for both the mother and the fetus. Others may potentially be harmful. You should always discuss every recommended test with your healthcare team and make sure they know that you are pregnant. Common tests used in the diagnosis of cancer include:
X-rays:
Research shows that the level of radiation used in diagnostic x-rays is low enough that it does not harm the fetus. Whenever possible, a lead shield is used to protect the abdomen during x-rays.
Computed tomography (CT or CAT) scans:
CT scans are similar to x-rays but much more detailed because they use higher doses of radiation. They can detect cancer or show whether cancer has spread. CT scans of the head and chest are generally considered safe during pregnancy because they do not expose the fetus directly to radiation. Whenever possible, a shield should be used to cover the abdomen during any CT scan in a pregnant woman. CT scans of the abdomen or pelvis should only be performed if there is no alternative. You should discuss with your doctors whether the scan is truly necessary and what the potential risks are.
Other imaging and diagnostic tests:
Magnetic resonance imaging (MRI), ultrasound, and biopsies are generally considered safe during pregnancy.
Serum tumor markers:
Although serum tumor markers can be useful for the diagnosis, follow-up, and management of cancer patients, their sensitivity and specificity are reduced during pregnancy due to significant physiological changes in serum levels. Commonly used tumor markers such as CA 15-3, SCC, CA 125, and AFP are elevated in pregnancy and are therefore unreliable. On the other hand, CEA, CA 19-9, LDH, AMH, and HE-4 levels are not commonly elevated in pregnancy and may, in theory, provide additional information. There are some exceptions: inhibin B levels may rise during the third trimester of a normal pregnancy, and LDH may be elevated as a marker of pregnancy-related hypertensive disorders.
How Is Cancer Treated During Pregnancy?
Planning cancer treatment during pregnancy requires a multidisciplinary team of different medical and healthcare providers working together. This includes a medical oncologist, radiation oncologist, obstetrician, high-risk obstetric specialists (maternal-fetal medicine) and other relevant specialists. This team will review and compare the best treatment options and potential risks for you. They will consider several factors, including the stage of your pregnancy and the type, size, and stage of the cancer. While you are deciding on cancer treatment, your doctors will also discuss your preferences with you. Throughout treatment, they will monitor you closely to ensure that your baby remains healthy.
Sometimes doctors may recommend delaying or avoiding certain treatments during pregnancy. For example:
- During the first three months of pregnancy, some cancer treatments are more likely to harm the fetus. For this reason, your doctors may suggest postponing treatment until the second or third trimester.
- Some treatments may harm the fetus at any point during pregnancy. Doctors generally try to avoid using these treatments until after the baby is born. Radiation therapy, for example, is a powerful treatment that uses high-energy x-rays to destroy cancer cells. Depending on the dose and the part of the body being treated, there may be risks to the fetus throughout pregnancy.
- If doctors detect cancer later in pregnancy, they may recommend starting treatment after the baby is born.
- For certain early-stage cancers, such as early-stage cervical cancer, doctors may recommend postponing treatment until after delivery.
Which Cancer Treatments Can I Receive During Pregnancy?
Some cancer treatments are safer than others during pregnancy:
Surgery:
During surgery, doctors remove the tumor and some of the surrounding healthy tissue. Surgery generally carries very little risk to the fetus. Overall, surgery is considered the safest cancer treatment during all stages of pregnancy. Sentinel lymph node sampling with radioactive tracers in the axilla to determine the extent of tumor spread is also generally considered harmless.
Cancer drugs (Chemotherapy):
Your treatment plan may include the use of drugs like chemotherapy to kill cancer cells. Chemotherapy can only be used at certain times during pregnancy:
- In the first trimester, chemotherapy carries a risk of congenital anomalies (birth defects) or pregnancy loss. This is the period when the baby’s organs are still forming.
- In the second and third trimesters, doctors may use certain types of chemotherapy that are associated with low risk for the fetus. Because the placenta acts as a protective barrier for the baby, some drugs do not cross it at all, while others cross only in small amounts. Research shows that children who were exposed to chemotherapy during pregnancy do not appear to have more health problems than children whose mothers did not receive chemotherapy. This includes the immediate postnatal period and the child’s growth and development.
In the later stages of pregnancy, chemotherapy may cause side effects such as low blood counts in both mother and baby. This can increase the risk of infection and may indirectly harm the baby during or shortly after birth.
Your doctors may consider inducing early delivery to protect the baby from cancer treatment. This is a decision that must be made very carefully with you, balancing both your health and your baby’s health.
If you receive chemotherapy after the baby is born, you should not breastfeed, because chemotherapy drugs can pass to the baby through breast milk.
Radiation Therapy (Radiotherapy):
Typical therapeutic radiation doses in radiotherapy range between 40–70 Gy and are 10⁴–10⁵ times higher than the doses used for diagnostic procedures. Due to the potentially harmful effects of high-dose radiation on the developing fetus, radiotherapy is not among the first-line treatment options during pregnancy. However, in certain cancers located far from the abdomen (more than 30 cm away), such as cancers of the head and neck, breast, or extremities, radiation therapy may rarely be given after careful dose calculation, full approval by the whole medical team, and implementation of fetal protective measures.
In medically urgent situations—such as spinal cord compression or superior vena cava syndrome (compression of the large vein in the chest)—radiation therapy may be considered after medical consensus in order to improve the mother’s condition.
Endocrine therapies (such as estrogen or progesterone antagonists, tamoxifen, etc.)
are not used during pregnancy.
Targeted molecular therapies
(e.g. imatinib, rituximab, trastuzumab, lapatinib, bevacizumab, ipilimumab, PD-1/PD-L1 inhibitors, etc.) are used increasingly in modern oncology to target specific molecules involved in the growth and spread of malignant cells. However, most of these drugs are relatively new, and there is insufficient accumulated data about their effects when exposure occurs during pregnancy. Therefore, their use in pregnancy is not recommended.
Does Pregnancy Affect Cancer Treatment?
Pregnancy itself does not appear to reduce how effective cancer treatment is. However, diagnosing cancer at a later stage or delaying the start of treatment can affect treatment outcomes. You should discuss with your doctors how different factors may influence your cancer risk and what to expect during the recovery period after treatment.
Coping With a Cancer Diagnosis During Pregnancy
Although it is normal for pregnant women with cancer to focus on their unborn child rather than themselves, it is important to understand that the best way to have a healthy baby is to take good care of yourself during pregnancy. If your doctor recommends it, consider cancer treatment during pregnancy.
You should also give yourself time, accept help from others, rest, and try to eat as healthily as possible to support your immune system during and between treatments. Remember that you are not alone; every year, approximately 1 in 1,000 pregnant women is diagnosed with cancer.
If you are receiving cancer treatment while pregnant, make sure you have an open dialogue with your healthcare team about how treatment may affect you and your baby. One of the most important questions for someone newly diagnosed with cancer during pregnancy is:
“How would I be treated if I were not pregnant?”
The next question should be:
“Has this treatment been given before in pregnancy, and what were the risks and outcomes for the children?”
Pregnancy After Cancer Treatment
In general, pregnancy after cancer treatment is safe for both mother and baby. Pregnancy does not appear to increase the risk of cancer coming back. However, some women may be advised to wait several years before trying to conceive. The recommended waiting time depends on several factors:
- The type and stage of cancer
- The type of treatment received
- A woman’s age
Some centers advise women not to become pregnant within the first 6 months after completing chemotherapy, noting that damaged eggs are likely to leave the body within this period. Others recommend waiting 2 to 5 years before trying to have a baby. The reason is that the risk of cancer recurrence can be higher during the earlier years, and cancer treatment during pregnancy is more complex.
How Can Previous Cancer Treatments Affect Future Pregnancies?
Previous cancer treatments can affect future pregnancies in several ways:
Radiation therapy:
Radiation can affect supporting tissues and the blood flow to the uterus. It can also increase the risk of miscarriage, preterm birth, low birth weight, and other complications.
Cervical surgery:
Partial or complete removal of the cervix can increase the likelihood of miscarriage or preterm birth (cervical insufficiency), because the cervix may not be able to support a growing pregnancy. In such cases, patients should be evaluated in advance, and before conception a stitch can be placed in the cervix (preferably an abdominal cerclage) to minimize the risk. With this approach, the rate of taking a healthy baby home can exceed 90%.
Chemotherapy:
Anthracycline chemotherapy includes treatment with doxorubicin, daunorubicin (Cerubidine), epirubicin (Ellence), and idarubicin (Idamycin). These treatments can damage heart muscle cells and weaken the heart. As a result, the heart needs to work harder during pregnancy and birth. Sometimes anthracycline chemotherapy is used together with radiation therapy to the upper abdomen or chest. This combination increases the risk of heart problems.
Questions You May Want to Ask Your Medical Team
If you are pregnant and have recently learned that you have cancer, you may want to ask your healthcare team the following questions:
- How much experience do you have in treating pregnant women with cancer?
- How will you coordinate my care with my obstetrician?
- Do I need any special tests to learn more about the cancer? Does each test carry any risk for my baby?
- What are my cancer treatment options?
- Which treatment plan do you think is best, and why?
- Should I start treatment immediately, or can/should I wait?
- Could delaying treatment affect my chances of curing this cancer?
- Is it safe to continue the pregnancy?
- What are the short- and long-term risks of treatment for me and for my baby?
- How will my baby’s health be monitored during my cancer treatment?
- Will my cancer treatment affect how I give birth?
- Will I be able to breastfeed?
- Is there a counselor, psycho-oncologist, psychologist/psychiatrist, or another team member who can help me cope with the emotional impact of this diagnosis?
- What additional support services and resources are available for me and my family?
Obstetrics and Gynecology Specialist
Prof. Dr. Arda Lembet
