Breast milk jaundice

Alternative names:

jaundice associated with breast feeding; jaundice associated with nursing

Definition:

Persistent jaundice in the newborn caused by a hormone found in breast milk.

Causes, incidence, and risk factors:

Jaundice in the newborn, or neonatal jaundice, is a common and normal occurrence. Bilirubin, the yellowish pigment responsible for jaundice, is a chemical that dissolves readily in fats or oils but is not very water soluble. Bilirubin is eliminated by chemically hooking a sugar molecule to the bilirubin molecule, which then makes the bilirubin water soluble. In its water soluble form, bilirubin can be excreted in the urine.

Breast milk contains a hormone, pregnanediol, that interferes with the body's ability to hook the sugar onto the bilirubin. Some mothers, approximately 1 out of 200, have breast milk pregnanediol levels high enough to severely interfere with this process. Their infants become more jaundiced, have higher bilirubin levels, and the jaundice lasts longer than in other infants. Some breast fed infants may remain mildly jaundiced up to their third month of life. No illness has been attributed to the elevated levels of bilirubin caused by this means, but the high levels (sometimes approaching 20 mg/100cc) are worrisome.