X-rays, MRIs, CAT scans, Intravenous Pyelogram (IVP), ultrasound, mammograms, etc. do not affect breastfeeding. Barium is sometimes used as a contrast agent; it is not absorbed orally and thus does not affect breastfeeding.
Sometimes radiocontrast dyes are used to aid the imaging – these dyes do not require that mom interrupt breastfeeding.
“Although most package inserts for these products suggest that nursing mothers postpone breastfeeding their babies for 24 hours after use, research indicates that this is not necessary (Kubik-Huch 2000; Rofsky 1993; Nielson 1987; Fitz-John 1982). In Medications and Mothers’ Milk (2002), Dr. Thomas Hale explains that ‘Although under usual circumstances iodine products are contraindicated in nursing mothers (due to ion trapping in milk), these products are unique in that they are extremely inert and do not release free iodine… They are virtually unabsorbed after oral administration’ (Hale, p. 480). In mothers who have used these agents while breastfeeding, no effects have been reported in their nursing babies (Kubik-Huch 2000; Nielson 1987). These preparations are also used in children for diagnostic purposes.”
From: Mohrbacher N, Stock J. The Breastfeeding Answer Book. 3rd Revised Edition. Schaumburg, Illinois: La Leche League International; 2003:508.
“Because of the very small percentage of iodinated contrast medium that is excreted into the breast milk and absorbed by the infant’s gut, we believe that the available data suggest that it is safe for the mother and infant to continue breastfeeding after receiving such an agent… Review of the literature shows no evidence to suggest that oral ingestion by an infant of the tiny amount of gadolinium contrast agent excreted into breast milk would cause toxic effects. We believe, therefore, that the available data suggest that it is safe for the mother and infant to continue breastfeeding after receiving such an agent.”
From: American College of Radiology Committee on Drugs and Contrast Media. Administration of Contrast Medium to Breastfeeding Mothers. ACR Bulletin. October 2001;57(10):12-13.
“Contrast medium is not appreciably deionated. In addition, the absorption of hydrophilic contrast medium is minimal when it is given orally for imaging studies of the gastrointestinal tract. Since no toxicity is known in full-term infants even after the direct administration of contrast medium, the use of these compounds by breastfeeding women appear to pose no risk to their infants.”
From: Ito S. Drug therapy for breast-feeding women. N Engl J Med. Jul 13, 2000;343(2):118-26. See particularly “Iodine-Containing Contrast Medium and Antiseptic Agents” on p. 123-124.
|Contrast dyes & radiopaque agents|
|Generic name||Trade Name||Pregnancy Risk Category**||Lactation Risk Category**|
|* approved by the AAP for use in breastfeeding mothers: American Academy of Pediatrics Committee on Drugs. Transfer of drugs and other chemicals into human milk. Pediatrics. Sep 2001;108(3):776-89.
** Hale TW. Medications and Mothers Milk. 14th Edition. Amarillo, Texas: Hale Publishing; 2010. (More radiocontrast agents are listed in Hale’s book.)
- Breastfeeding and Medications by Jack Newman, MD, FRCPC
- Myths of Breastfeeding by Jack Newman, MD, FRCPC
- Breastfeeding and Cancer by Diana West, BA, IBCLC discusses many diagnostic procedures.
References (most recent listed first)
- JAW Webb, HS Thomsen, SK Morcos and members of the Contrast Media Safety Committee of the European Society of Urogenital Radiology (ESUR). The use of iodinated and gadolinium contrast media during pregnancy and lactation. Eur Radiol. 2005 Jun;15(6):1234-40.
- Riordan J. Breastfeeding and Human Lactation. 3rd ed. Boston and London: Jones and Bartlett; 2004:159-161.
- Hale TW. Medications and Mothers Milk. 11th Edition. Amarillo, Texas: Pharmasoft Publishing; 2004.
- Mohrbacher N, Stock J. The Breastfeeding Answer Book. 3rd Revised Edition. Schaumburg, Illinois: La Leche League International; 2003:508, 609-612.
- American College of Radiology Committee on Drugs and Contrast Media. Administration of Contrast Medium to Breastfeeding Mothers. ACR Bulletin. October 2001;57(10):12-13.
- American Academy of Pediatrics Committee on Drugs. Transfer of drugs and other chemicals into human milk. Pediatrics. Sep 2001;108(3):776-89.
- Ito S. Drug therapy for breast-feeding women. N Engl J Med. Jul 13, 2000;343(2):118-26.
- Kubik-Huch RA, et al. Gadopentetate Dimeglumine Excretion into Human Breast Milk during Lactation. Radiology. 2000;216:555-558.
- Hylton NM. Suspension of Breast-feeding following Gadopentetate Dimeglumine Administration (Editorial). Radiology. 2000;216:325-326.
- Rofsky NM, Weinreb JC, Litt AW. Quantitative analysis of gadopentetate dimeglumine excreted in breast milk. J Magn Reson Imaging. Jan-Feb 1993;3(1):131-2.
- Nielsen ST et al. Excretion of iohexol and metrizoate in human breast milk.
Acta Radiol. Sep-Oct 1987;28(5):523-6.
- FitzJohn TP, Williams DG, Laker MF, Owen JP. Intravenous urography during lactation. Br J Radiol. Aug 1982;55(656):603-5.
Use of radioisotopes sometimes requires temporary weaning. The length of time will depend upon the type of radioactive material used, the dose, the age of the baby, whether baby is getting anything other than breastmilk, and how often mom expresses milk. If use of a particular radioisotope requires that you wean temporarily (some don’t), you’ll want to pump regularly while the radiation is working out of your system to reduce radiation exposure to breast tissue. At least 97% of the radioactivity is gone from your body in 5 half-lives – after this point it is generally considered safe to breastfeed (but other factors may also need to be considered). The more often you pump, the more quickly the radioactivity will be eliminated from your body. It may be possible to have your milk tested for radioactivity, perhaps by the radiology department at the hospital, to help determine when it is safe to return to breastfeeding.
Important note: If you do suspend breastfeeding due to use of radioactive isotopes, it is important to pump regularly during this time. See also Maintaining milk supply when baby is not nursing. You do not need to dump this milk. It can be dated, frozen and used after 5+ half-lives of the radioisotope have passed (after 5 half-lives, 96.9% of the radiation is gone; after 10 half-lives, 99.9% of the radiation is gone). You may also get your milk checked for radiation by your radiology/nuclear medicine department.
Specifics on certain tests
Always check with your nuclear medicine department to find out exactly which radioisotope will be used. Once you have this information, you can look it up in the US Nuclear Regulatory Commission table and other references.
HIDA/Hepatobiliary scan (for gall bladder problems) – This test usually uses Tc-99m-Choletec or Hepatolite, which should not require an interruption of breastfeeding for doses of 4mCi or less; or Tc-99m-DISIDA, which should not require an interruption of breastfeeding (see the links below for detailed information).
Bone Scan – This test usually uses Tc99m-DP or -HDP, which should not require an interruption of breastfeeding for doses of 30 mCi or less (see the links below for detailed information).
Thyroid Scan or Treatment – see Breastfeeding and Thyroid Problems: Diagnostic Testing & Treatments
More information & references
For the most up-to-date specifics on different radioactive agents, see the latest edition of Medications and Mother’s Milk by Thomas Hale, and/or the LactMed online database, maintained by the National Library of Medicine. Breastfeeding helplines are another way to gather information, including the InfantRisk Center Helpline – (806) 352-2519, which is dedicated to providing up-to-date evidence-based information on the use of medications during pregnancy and breastfeeding.
U.S. Nuclear Regulatory Commission information on Radiopharmaceuticals for Breastfeeding Patients (1/27/03) from Dr. Thomas Hale’s Breastfeeding Pharmacology website
Breastfeeding and Cancer by Diana West, BA, IBCLC discusses many diagnostic and therapeutic procedures.
In: Stabin MG, Breitz HB. Breast milk excretion of radiopharmaceuticals: mechanisms, findings, and radiation dosimetry. Journal of Nuclear Medicine 2000; 41(5):863-873.
Nuclear Medicine Guidelines for Breastfeeding Mothers (revised 9/3/96) from the Radiation Internal Dose Information Center (RIDIC) at the Oak Ridge Institute for Science and Education.
Hale TW. Medications and Mothers Milk, 14th Edition. Amarillo, Texas: Hale Publishing, 2010.
Lawrence R and Lawrence R. Breastfeeding: A Guide for the Medical Profession, 5th ed. St. Louis: Mosby, 1999, p. 387-8,510,521-523, 810-815.
Mohrbacher N, Stock J. The Breastfeeding Answer Book, Third Revised Edition. Schaumburg, Illinois: La Leche League International, 2003, p. 609-612.
Riordan J. Breastfeeding and Human Lactation, 3rd ed. Boston and London: Jones and Bartlett, 2004, p. 159-161, 481.