Is it Possible to Breastfeed After Diagnostic Breast Surgery?

Breastfeeding after diagnostic breast surgery is absolutely possible. Any damage to ducts and nerves, though, may reduce the amount of milk a mother can make. However, every drop of milk is tremendously beneficial for your baby and there are many ways to increase milk production.

Any procedure that invades breast tissue, including diagnostic breast procedures, has the potential to damage ducts or nerves. More obvious procedures include biopsies that remove sample breast tissue, aspirations to remove infectious or suspicious fluids from the breast, and excisions to remove tissue such as lumps. These frequently have a mild to moderate impact on lactation. More invasive procedures such as heart and lung surgeries may require cutting through breast tissue. One of the most vulnerable periods for breast tissue is before puberty. The undeveloped mammary gland is very small, and invasive cuts during that vulnerable period can interfere with a greater number of ducts and nerves simply because they are closer together. This affects the final structure of the breast, including the number of intact nerves and ducts.(1) Ultimately, the effect of the diagnostic or therapeutic procedure upon the amount of milk a woman will be able to make depends upon the type of procedure, the timing, and whether or not she is currently lactating.

How is Breastfeeding Affected if Diagnostic Procedures are Necessary when a Mother is Still Nursing?

It is common for mothers to be instructed to wean for days, weeks, or months prior to diagnostic imaging or aspiration or biopsy.  Diagnostic imaging techniques are more difficult to interpret during lactation, but it is not impossible to do so.  Weaning is neither practical nor necessary. (2), (3)  Abrupt weaning can be psychologically traumatic for both you and your nursling, no matter how old he is.  It could also lead to plugged ducts and breast infection (mastitis) from sudden milk stagnation. 

Surgeons may not be aware that weaning is a gradual process; milk can continue to be produced for many months.  There is almost certain to be residual milk in the ducts when surgery is performed on a recently lactating woman.  Although it may be difficult for the surgeon during the procedure, the milk is bioactive, containing anti-infectious and anti-inflammatory agents, and therefore, rather than contaminating the wound, will reduce the likelihood of infection and accelerate healing.  To minimize obstruction of the procedure, thoroughly drain your breast(s) by nursing or pumping immediately before the diagnostic or ablative surgery.

Breastfeeding and Cancer

There are many myths about breastfeeding when a mother has cancer or after her cancer has been removed.  For instance, mothers have been warned that cancer can be transmitted to their babies by suckling a cancerous breast.  This has never been documented in humans and is highly unlikely.  Another myth is that a baby will refuse to suckle a cancerous breast.  This is not necessary true, although babies have been known to occasionally refuse a breast when the milk taste changes or the milk supply decreases as a result of a malignant mass. (4)   There is no evidence that breastfeeding increases the risk of breast cancer recurrence, or that it carries any health risk to the child.(5)

In consideration for a mother with cancer, she may be told that weaning is necessary in order to “conserve her strength.”(6)  In fact, lactation decelerates the maternal metabolism, rendering it more efficient.  Breastfeeding is also more convenient and less time-consuming than bottle-feeding.  Most importantly, it provides an emotional connection and intimacy that is nurturing to both you and your baby when you both need it most.

Effects of Diagnostic Procedures upon Milk Safety

Ultrasound, aspiration, and biopsy procedures do not affect the quality or safety of the milk and are wholly compatible with breastfeeding.  The safety of radioactive diagnostic procedures while breastfeeding depends upon the type of radiation used.

Radiation and radioactive agents are common tools used in diagnostic procedures.  The compatibility of the radioactive procedure with breastfeeding depends upon the type of radiation used. 

Radiation exists in two forms: pure energy and particulate.  X-rays use pure energy and are similar to visible light, but contain more energy.  The effects of an x-ray can be likened to using a flash while taking a photograph; after the x-ray is taken, the radiation is no longer present in the same way that the light from a camera is no longer present after the flash has discharged.  Mammograms and CT scans use pure energy x-ray radiation, produced with a specialized light bulb.  It is not uncommon for mothers to be advised to “pump and dump” their milk for an arbitrary period of time subsequent to mammographic testing.  This is not necessary.  While x-ray radiation does have the ability to mutate DNA such that any live cells that have been exposed to it may mutate, resulting in cellular dysfunction or uncontrolled replication (i.e., cancer), the pure energy type of radiation used in mammogram and CT scan testing does not collect in the milk and is therefore compatible with uninterrupted breastfeeding.

Radioactive agents contain particulate radiation, which consists of atoms with unstable nuclei that release radiation when they deteriorate, which is useful in diagnostic imaging to delineate subtle tissue structures. Ingestion or injection of a radioactive agent results in radiation residing in the body until the radiation completely disintegrates or is excreted.  Consumption or injection of particulate radiation, such as during a ductogram, MRI, MIBI scan, or PET scan, during lactation will result transference of radioactive substances into the milk during milk synthesis. The radioactive toxicity and compatibility with breastfeeding depends upon the substance used.  The radiopaque and radiocontrast agents typically used in the ductogram, MRI, MIBI scan, or PET scan diagnostic tests are extremely inert and are virtually unabsorbed after oral administration.(7) These products are commonly used in pediatrics for diagnostic purposes and no effects have been reported among babies who have ingested milk subsequent to radioactive agent imaging procedures.(8), (9)    It is not necessary to interrupt breastfeeding when radiopaque and radiocontrast agents are used in imaging procedures.(10), (11), (12), (13)

The use of radioactive isotopes during diagnostic testing or therapy, however, is contraindicated during breastfeeding as such compounds accumulate in milk and are, therefore, hazardous to the infant who ingests it.  It is not necessary for you to wean completely in order to undergo a procedure employing radioactive isotopes.  You need only interrupt breastfeeding temporarily, feeding your infant previously pumped milk or formula until your milk is demonstrated by testing to be no longer radioactive (most hospital radiology departments are able to perform the tests).  Frequent pumping during this time will protect your milk production and accelerate removal of radiation from your body.(14)

Implications for Breastfeeding After Radiation Therapy

Therapy with pure energy radiation is injurious to all breast tissue, including the lactation tissue.  This effect is usually permanent. (15), (16), (17)   An irradiated breast is likely to produce a substantially reduced milk supply, even to the point of no milk at all.  However, lactation will be unaffected on the breast that did not receive radiation.  If radiation therapy is administered during active lactation, you can continue to breastfeed on the other breast.(18) By taking steps to increase milk production, it is possible that a full milk supply can be achieved on that side. If full milk production does not develop, supplementation can be given in a manner that is supportive of breastfeeding so that the breastfeeding relationship is preserved.

Effects of Chemotherapy upon Lactation Functionality

Diagnostic breast surgery techniques

(8) Kubik-Huch, R., Gottstein-Aalame, N., Frenzel, T., et al. Gadopentetate dimeglumine excretion into human breast milk during lactation. Radiology 2000 Aug;216(2):555-8.

(9) Nielsen, S., Matheson, I., Rasmussen, J., et al. Excretion of iohexol and metrizoate in human breastmilk. Acta Radiol 1987; 28(5):523-526.

(10) Kubik-Huch, R., Gottstein-Aalame, N., Frenzel, T., et al. Gadopentetate dimeglumine excretion into human breast milk during lactation. Radiology 2000 Aug;216(2):555-8.

(11) Rofsky, N., Weinreb, J., Litt, A. Quantitative analysis of gadopentetate dimeglumine excreted in breast milk. J Magn Reson Imaging 1993 Jan-Feb;3(1):131-2.

(12) Nielsen, S., Matheson, I., Rasmussen, J., et al. Excretion of iohexol and metrizoate in human breastmilk. Acta Radiol 1987; 28(5):523-526.

(13) Fitz-John, T. et al. Intravenous urography during lactation. Br J Radiol 1982; 55:603-05.

(14) Mohrbacher, N. The Breastfeeding Answer Book, 3rd Revised Edition.  La Leche League International. Schaumburg, Illinois: 2004.

(15) Neifert, M. Breastfeeding after breast surgical procedure or breast cancer. NAACOGS Clin Issu Perinat Womens Health Nurs 1992 3:4 673-82.

(16) David, F. Lactation following primary radiation therapy for carcinoma of the breast. Int J Radiat Oncol Biol Phys 1985 Jul;11(7):1425.

(17) Higgins, S. and Haffty, B. Pregnancy and lactation after breast-conserving therapy for early stage breast cancer.  Cancer 1994 Apr 15;73(8):2175-80.

(18) Mohrbacher, N. The Breastfeeding Answer Book, 3rd Revised Edition.  La Leche League International. Schaumburg, Illinois: 2004.

(19) Hale, T.  Medications and Mothers’ Milk, 12th edition.  Amarillo, TX: Pharmasoft Publishing, 2006.

(20) Helewa, M., Levesque, P., Provencher, D., et al; Breast Disease Committee and Executive Committeee and Council, Society of Obstetricians and Gynaecologists of Canada. Breast cancer, pregnancy, and breastfeeding.  J Obstet Gynaecol Can 2002 Feb;24(2):164-80.