Cancer During Pregnancy: Diagnosis & Care

Being diagnosed with cancer while pregnant is rare. It is also one of the situations where people get the worst information from well-meaning friends and from the internet. The most common assumption is that treatment is impossible and the pregnancy must end. That is not what modern cancer care assumes. Many cancers can be treated during pregnancy. Many pregnancies go on to a healthy delivery.

What is true is that the decisions are genuinely complicated. They are made by a larger team than usual. And they belong to the pregnant person.

Pregnancy makes cancer harder to spot. Breast tissue changes. Fatigue, nausea, bleeding and abdominal pain all have ordinary pregnancy explanations. So symptoms often get blamed on the pregnancy first. A lump or a symptom that does not settle deserves a workup, not reassurance. Pregnancy is not a reason to skip one.

Imaging is possible, with adjustments. Ultrasound and MRI without contrast are usually the first choices. Neither one uses ionizing radiation. Other scans may still be used when the information matters. Shielding or changed protocols can help, and a radiologist can advise on the expected exposure. Biopsies are done routinely during pregnancy. The point of staging is the same as at any other time. You need to know what is being treated before you decide how.

Ask what each test would change. Ask whether a lower-exposure test answers the same question.

Care during pregnancy is not run by one doctor. Expect a maternal-fetal medicine specialist (a doctor who handles high-risk pregnancies) alongside your oncologist. Expect a neonatologist, an obstetric anesthesiologist and a pharmacist too. Often a social worker or ethicist joins as well. The American Society of Clinical Oncology published a guideline on managing cancer during pregnancy in 2025. It describes the work as bringing together maternal-fetal medicine and medical oncology. It covers everything from the timing of diagnostic tests through delivery planning. It also covers the ethical and legal questions involved.

That guideline addresses something that often goes unspoken. It includes recommendations to support a patient's decision either to continue or to end a pregnancy. It notes that access to that choice differs by state. Whatever you decide, you are entitled to a clear explanation. You should hear what continuing the pregnancy would mean for your treatment. You should also hear what ending it would and would not change about your prognosis.

Questions worth asking the whole team together, in one room:

• Can this cancer be treated well without delaying treatment, and what does waiting cost?
• Which specific drugs are being proposed, and what is known about each in pregnancy?
• Is delivery timing being driven by my treatment, by the baby's development, or both?
• Who is coordinating between oncology and obstetrics, and who do I call first with a problem?
• What follow-up will the baby have after birth?

Our general list of questions to ask before treatment begins can be adapted for this conversation.

Some broad patterns hold across cancer types. The specifics depend on the diagnosis and on the stage of pregnancy.

Surgery can usually be done during pregnancy. It needs anesthetic and monitoring adjustments. The second trimester is often the most straightforward window.

Chemotherapy is a different question in the first trimester than later. The National Cancer Institute writes about cervical cancer treatment during pregnancy. It states that chemotherapy given in the second or third trimester does not usually harm the fetus. It states that chemotherapy is unsafe during the first trimester. The same page notes that radiation therapy is harmful throughout fetal development. Newer drug classes have much less pregnancy data behind them. That includes many targeted therapies and immunotherapies. Your team should say plainly when the honest answer is that the evidence is limited.

Delivery timing becomes part of the treatment plan. Teams generally try not to deliver very early for treatment reasons alone. They also try to schedule delivery away from recent chemotherapy, so blood counts have time to recover. Some treatments are held until after birth. Some are given before. Whether breastfeeding is possible depends on the specific drugs involved. Ask about it in advance rather than afterward.

This is a lonely diagnosis. The two groups you would normally lean on are other pregnant people and other cancer patients. Each group is having a very different experience. Hope for Two, also known as the Pregnant with Cancer Network, connects people who have been through cancer during pregnancy with those going through it now. Our support page has other starting points.

You will hear a great deal of confident opinion from people who have never faced this situation. The team in front of you has your full history and your stated priorities. They are a better guide than any of it.

You now have two sets of warning signs running at once, and they are handled by different people. Agree in advance who you ring first for what, and keep both numbers together. When something happens, say up front that you are pregnant and receiving cancer treatment.

• Call 911 or go to an emergency department if you have heavy vaginal bleeding that soaks through a pad quickly, severe abdominal pain, pain in the tip of your shoulder, or you feel faint, dizzy or pass out. Those signs need to be seen straight away at any stage of pregnancy.
• Call your maternity unit the same day if your baby is moving less than usual, you cannot feel movements any more, or the pattern of movements has changed. The NHS is blunt about this: do not wait for morning, ring even in the middle of the night. Any vaginal bleeding, a gush of fluid, or regular tightenings well before your due date also goes here.
• Call your cancer team straight away, at any hour, if your temperature reaches 100.4°F (38°C) or higher after chemotherapy, or you are shivering uncontrollably. Low white cells do not spare pregnant people. The CDC treats fever during chemotherapy as a medical emergency, so this one is not a message left for the clinic (CDC). If you cannot reach them quickly, go to an emergency department and say you are pregnant and on chemotherapy.
• Call your care team within a day or two if vomiting is stopping you keeping fluids or food down, one leg becomes swollen and tender, or the wound from cancer surgery turns red, hot or starts leaking.

• NHS — Vaginal bleeding in pregnancy
• NHS — Your baby's movements
• National Cancer Institute — Infection and Neutropenia during Cancer Treatment
• National Cancer Institute — Cervical Cancer Treatment during Pregnancy
• National Cancer Institute — Breast Cancer Treatment During Pregnancy
• National Cancer Institute — Cancer Staging