Supporting Breastfeeding

La Leche League Canada

Radiologic Procedures While Breastfeeding

on January 2, 2017

Mothers often ask if they must wean before having a medical diagnostic scan or x-ray. In most situations, weaning is not necessary.

The first step is to gather information about the type of testing that is being recommended. Useful information to collect is the name of the test and the name of the radio-contrast compound or radio-opaque contrast media (i.e. the drug taken or injected to make parts of the body show up when x-rayed or scanned) being used.


MRI Scan (magnetic resonance imaging)

  • Best for looking at soft tissue (brain, muscle, cancers, blood vessels, etc.), and can be used for looking at bone.
  • Does not use radioactive material, but does use radio-contrast medium that under magnetic field shows up body parts.
  • Contrast is not always used but does enhance the image. Contrast substance used most commonly is gadopentetate and it is not radioactive
  • Less than 0.04% of the dose of gadopentetate will appear in a mother’s milk and only 0.8% of that is absorbed by the baby.
  • Those with claustrophobia are given conscious sedation.


CT Scan (computerized axial tomography) or CAT scan.

  • Gold standard for looking at bleeding (clots), tumours, inflammation, bone or tissue injury, guiding passage of a needle etc.
  • Person takes a compound that contains iodine. Multiple x-rays are taken encircling the body, and the iodine reveals bones or tissues.
  • Contrast medium used is not radioactive. Contrast is not always used. Like for MRIs it is used to enhance imaging.
  • The iodine in the contrast material is bound to a molecule forming the compound.  The compound does not enter the milk in any noticeable amount. The compound does not release enough iodine to alter the infant’s thyroid function.


IVP (intravenous pyleogram), or lymphangiogram

  • Uses contrast media similar to MRI (see above)
  • Contrast medium is delivered by intravenous to show under x-ray the kidney, lymph nodes or blood vessels.


Radioactive Scans

  • A radioactive form of gallium (Ga), technetium (Tc), or iodine (I) is sometimes given to a mother before a test or used as a treatment.
  • In order to protect the baby from ingestion of the radioactive compound in breastmilk, weaning for a period of time is recommended.
  • Appropriate times for being off the breast are listed in Hale
  • Mother will need to express her milk during this time to maintain her supply.




Consider Other Options

If a mother has been told to wean her baby for one of the first three scans, she may be able to consider other options. Printed information can be shared with the doctor, such as pages from Medications and Mother’s Milk, Breastfeeding Answers Made Simple, or other references.
Has she asked her doctor if the test can be postponed or if another less invasive procedure is possible?  Has the doctor shown her evidence indicating that the baby must be weaned? Has she discussed with her doctor the risks of temporary weaning?


Support For Temporary Weaning

In the case where weaning is unavoidable, because the scan requires a radioactive contrast medium (the fourth scan above) which is not compatible with breastfeeding, a mother will require support as she decides how to cope with the situation. She may wish to prepare ahead by pumping and freezing breastmilk for use during the hours or days it takes the radioactive substance to leave her body. “Decay time” is the total time needed for the medium to leave her body. The term “half-life” refers to both the length of time it takes for ½ of the contrast medium to leave the body and the time it takes for the level of radioactivity to decrease by 50%. Decay time is usually 5-10 half-lives. You can prepare for pumping during the decay time and discarding breast milk safely should that be necessary.

In some cases, a mother may have to arrange for a caregiver for the baby during the “decay time”. Decay times and half-lives of many radioactive contrast agents are available from Hale or from the x-ray laboratory where the test is being done.

Note: This article was published in 2010. Updated resources may be available. For more detailed information and references, please refer to the article.



If you need more information or have a breastfeeding problem or concern, you are strongly encouraged to talk directly to an accredited La Leche League Leader. In Canada, Leaders can be located by clicking or Internationally

If you have found this article helpful, La Leche League Canada would appreciate your support. Your donation is essential and very much appreciated to help LLLC cover the cost of producing breastfeeding resources: or become a LLLC Friend



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