Nursing Mother Myths Washington DC

by Jack Newman, MD, FRCPC

Breastfeeding Myths

Nursing mothers cannot breastfeed if they have had X-rays.

Not true!

Regular X-rays such as a chest X-ray or dental X-rays do not affect the milk or the baby and the mother may nurse without concern. Mammograms are harder to read when the mother is lactating, but can be done and the mother should not stop breastfeeding just to get this done. Furthermore, there are other ways of investigating a breast lump. Newer imaging methods such as CT scan and MRI scans are of no concern, even if contrast is used. And special X-rays using contrast media? As long as no radioactive isotope is used there is no concern and the mother should not stop even for one feed. Herein are included studies such as intravenous pyelogram, lymphangiogram, venogram, arteriogram, myelogram, etc. What about studies using radioactive nucleotides (bone scans, lung scans, etc.)?

The baby will get a little radioactive nucleotide. However, as we often do these very same tests on children, even small babies, and the potential loss of benefits if the mother stops breastfeeding are considerable, the mother should, in my opinion, continue breastfeeding. If you feel you must stop for a period of time, express milk in advance so that the baby can be fed your milk and not formula. After two half lives, 75% of the compound will be out of your body. This is surely waiting long enough (the half life of technetium, which is used in most radioactive scans is only six hours, so that 12 hours after the injection, 75% of it will be out of your body). The exception is the thyroid scan using I131. This test must be avoided in breastfeeding mothers. There are many ways of evaluating the thyroid, and only very occasionally does a thyroid scan truly have to be done. If the scan must be done, doing it with I123 requires the mother to stop nursing for 12 to 24 hours only depending on the dose. Check first before taking the radioactive iodine-the test can wait until you know for sure. In many cases where the scan must be done, it can be put off for several months. Incidentally, lung scans with radioactive contrast no longer is the best test to rule out a lung clot. CT scan is now the preferred test to prove or disprove the diagnosis.

Breastfeeding mothers' milk can "dry up" just like that.

Not true!

Or if this can occur, it must be a rare occurrence. Aside from day to day and morning to evening variations, milk production does not change suddenly. There are changes which occur which may make it seem as if milk production is suddenly much less:

  • An increase in the needs of the baby, the so-called growth spurt. If this is the reason for the seemingly insufficient milk, a few days of more frequent nursing will bring things back to normal. Try compressing the breast with your hand to help the baby get milk (Handout #15, Breast Compression).

  • A change in the baby's behaviour. At about five to six weeks of age, more or less, babies who would fall asleep at the breast when the flow of milk slowed down, tend to start pulling at the breast or crying when the milk flow slows. The milk has not dried up, but the baby has changed. Try using breast compression to help the baby get more milk.