Treatment risks if pregnant


In recent years, girls have started having menstrual periods at younger ages. For this reason, it is St. Jude policy to screen for pregnancy at 10 years of age when medically appropriate. Sometimes medical treatments can delay the start of menstrual periods. However, a girl can still become pregnant even if she has never had a period or has stopped having periods because of the medical treatments.

Medical tests and treatments can severely damage an unborn child.

Parents: Please talk to your daughter about sex and pregnancy. She needs to know the risks to an unborn child from cancer tests and treatments.

These treatments, medicines, and imaging tests can seriously injure an unborn child or cause birth defects:

  • Chemotherapy (cancer fighting drugs)
  • Radiation therapy
  • X-rays
  • CT scans
  • Nuclear medicine scans
  • Any type of sedation or anesthesia (drugs that help a person sleep or relax during tests or procedures)
  • Many other medicines

The US Food and Drug Administration (FDA) created a letter category system for medicines based on how much risk they pose when used during pregnancy (see table below). Medicines with known harmful effects to an unborn child are placed in categories “D” and “X”.

FDA pregnancy risk categories for drugs

Category Description
 D There is evidence of risk to the unborn child. However, benefits in certain serious cases may make it OK to use the drug during pregnancy despite its risks. The doctor will help decide if the benefits outweigh the risks.
There is evidence in animals or humans of birth defects or other risks to the unborn child. The drug is not used during pregnancy because it will probably cause more harm to the unborn child than it will benefit the patient.

Treatment can affect menstrual periods

Chemotherapy, radiation therapy, bone marrow transplants, and other medical treatments can change how often you have your menstrual periods or it can make them stop all together. If you have not yet started your periods, you may start later than you normally would have.

You can become pregnant even if you are not having periods

If you have sex, you can become pregnant. No medical treatments will prevent pregnancy if you are having sex.

What to do if you have been having sex

Please talk in private to one of your caregivers at St. Jude before you have any tests or treatments. You can talk to a nurse, nurse practitioner, physician’s assistant, doctor, X-ray technologist, radiologist, social worker, or child life specialist. You can also call the St. Jude Help Line (901-595-2999) if it would be easier for you. This fact must be shared with your doctor, so that we can protect you and the unborn child if you are

What will happen if you have been having sex

We will perform a test to find out if you are pregnant. If you are, we can still treat you for your disease. However, we will take extra care to protect the health of the unborn child. We will talk to you about your treatment plan before any changes are made.

What to do if you have already started tests and treatment

If you think that you may be pregnant after you have had medical treatments or tests, it is still important for you to tell someone! It will help us plan the rest of your treatment or follow-up care. Please help us protect your unborn child by telling a staff member if there is any chance that you could be pregnant.

How to avoid test or treatment delays

The only way to ensure the safety of an unborn child is to be certain that you are not pregnant before you have any tests or treatments. If you might be pregnant, please tell a staff member in your primary clinic as soon as you check in. The staff will order a urine or blood test right away. The test must be done before you have any other tests or treatments. If this pregnancy test is needed, it might cause a delay. In some cases, the staff may need to cancel your other tests or treatments because of this delay.


To learn more about treatment risks if you are having sex, please talk to your St. Jude doctor or another staff member that you trust. Locally, call 901-595-3300. If you are outside the Memphis area, dial toll-free 1-866-2STJUDE (1-866-278-5833), and press 0 once the call is connected.


This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.

St. Jude complies with health care-related federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex.

ATTENTION: If you speak another language, assistance services, free of charge, are available to you. Call 1-866-278-5833 (TTY: 1-901-595-1040).

ATENCIÓN: si habla español, tiene a su disposición servicios gratuitos de asistencia lingüística. Llame al 1-866-278-5833 (TTY: 1-901-595-1040).

تنبيه: إذا كنت تتحدث باللغة العربية فيمكنك الاستعانة بخدمات المساعدة اللغوية المتوفرة لك مجانا. .يرجى الاتصال بالرقم. 5833-278-866-1  (الهاتف النصي: 1040-595-901-1).