Cancer during Pregnancy – What to Expect

By (embryologist) and (fertility counselor).
Last Update: 11/11/2014

Suffering from cancer during pregnancy is uncommon but may sometimes happen. The major problem for a pregnant woman that has to endure cancer is the delay in the diagnosis of the illness. It’s estimated that there’s one pregnant woman with cancer in every 1,000 pregnancies. Only in Spain 120 cases of pregnant woman with cancer are diagnosed every year.

Provided below is an index with the 5 points we are going to expand on in this article.

Effects of pregnancy on cancer

The delay in detecting cancer has as a consequence that when the diagnosis comes, the illness is at a more advanced stage. It’s vital that the pregnant woman knows the risk and pays special attention to the changes produced during pregnancy, especially in the mammary glands, to make sure that are those typical of pregnancy.

Pregnancy does not worsen the prospects of getting over cancer. According to some studies the survival prospects of pregnant and not pregnant women are similar when the illness is diagnosed at the same state. A delay in the diagnosis between 3 to six months increases the risk of metastasis approximately in 5 to 10%.

The most common cancers pregnant women can suffer from are: breast cancer, cervix cancer, lymphoma and leukaemia, malignant melanoma, and less frequently, ovarian cancer, endometrial cancer or thyroid cancer.

Most common types of cancer

The following sections will introduce you to the most common types of cancer in females:

Breast cancer

It’s estimated that its frequency is one case in every 3,000 pregnancies and it’s more common in women over 30.

Breast tumours are in some cases hormone-sensitive; this means that they are sensitive to the hormonal changes such as estrogenic hormones during pregnancies.

This sensitivity may lead to the think that it is advisable to interrupt pregnancy so that the tumour development decreases and the treatment can be carried out without risks. However, current studies about this subject demonstrate that the survival of pregnant patients with breast cancer does not increase even though pregnancy is interrupted.

Currently this cancer can be treated without it presenting any risks for the foetus, being mastectomy the most common treatment and the most advisable.

Cervix cancer

It’s estimated that there are 1 to 13 cases in every 10,000 pregnancies. This, however, may vary.

The diagnosis of this kind of cancer in pregnant women can be more premature, due to the check-ups that are carried out. The diagnosis methods are the same that for not pregnant women.

The treatment is surgical. Once diagnosed, the risk of carrying out the treatment must be valued and decided if it’s better to wait until the foetus can be born.

Lymphomas and leukaemias

This kind of tumours need of chemotherapy ever since the first day that they are diagnosed. Since the main medicines used are teratogenic drugs and the treatment can be linked to complications such as blood toxicity, infections and secondary complications, it’s advisable to interrupt pregnancy if it’s during the first trimester and value its prognosis if it’s in the second trimester.

Malignant melanoma

When we talk about malignant melanoma, we are talking about these coloured tumours on the skin. These are the most common and severe cases of skin cancer: freckles or moles with irregular edges or size changes.

There are around 3 to 5 cases in every 100,000 pregnancies. Its premature diagnosis is of vital importance, since, if detected at an early stage the woman can easily get over them. According to some studies, the prognosis for pregnant and not pregnant women is the same, for melanoma doesn't affect pregnancy negatively.

It’s treatment depends on the type and stadium. When it’s easily localised it’s treated surgically at any moment of pregnancy and local anaesthetics are used. When it’s spread, chemotherapy or immunotherapy is required, but only if women are in the second or third quarter of pregnancy. If the cancer is at an advanced stage, treatment only delays the illness.


If we focus our attention on the breasts, physical exploration is the first detection method for women. If the breast hardens or there are inflammation signals, this must not be considered as normal changes during pregnancy.

Clinical exploration carried out by a specialist in these women is not easy. If there’s any sign of doubt, additional tests will be performed.

The biopsy is the diagnosis test that can be performed during any stage of pregnancy without it having any impact on the mother or the foetus.

There are several radiologic methods that can be used and don’t involve any risk for the foetus, such as thorax X-ray photograph or thorax ultrasound scan. Magnetic resonance, X-ray computed tomography and bone X-ray radiographies among others, are not advisable.

Before carrying out any kind of test, the exposure time and the radiation doses must be considered. The first trimester of pregnancy is the most delicate and exposing the foetus to radiation during this period may cause congenital malformations.


The oncologist will inform the patient firstly about which treatment is the best in her case. Doctors will take into account the impact of pregnancy in cancer and the effects of cancer, as well as its treatment, on the mother and the foetus.

Once she knows the risks, she’ll have to decide whether she wants to interrupt pregnancy, as long as it’s permitted according to current legislation.

Usually pregnant women can go through most of the treatments for cancer, depending on the type of it. According to several studies, the survival percentage of pregnant women with cancer that carry out the treatment during pregnancy is superior to the ones that don’t do it, 79% to 45%.

These women can go through surgical interventions with general anaesthetics and can go through chemotherapy once the first trimester has passed. Radiotherapy is not advisable. Women that delay the treatment until the baby is born don’t have the same survival chances as women who carry out the treatment right after the diagnosis.

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 Teresa Rubio Asensio
Teresa Rubio Asensio
BSc, MSc
Master's Degree in Medicine and Reproductive Genetics from the Miguel Hernández University of Elche (UHM). Teacher of different Clinical Embryology courses at the UHM. Member and writer of scientific contents at ASEBIR and ASPROIN. Embryologist specializing in Assisted Procreation at UR Virgen de la Vega. More information about Teresa Rubio Asensio
Adapted into english by:
 Sandra Fernández
Sandra Fernández
B.A., M.A.
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

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