Does iodine contrast cross into breast milk and is it safe for the infant?

From the Guidelines

Iodinated contrast agents used in imaging studies do cross into breast milk, but in very small amounts that are considered safe for the infant, and breastfeeding can be continued without interruption after a mother receives iodinated contrast media. The amount of iodinated contrast excreted into breast milk is less than 0.01% of the administered dose, and even less is absorbed by the infant's gastrointestinal tract, posing no significant risk to the nursing infant 1. The American College of Radiology and other medical organizations have concluded that it is not necessary to suspend breastfeeding after receiving iodinated contrast, as the contrast is rapidly cleared from the mother's bloodstream, primarily through kidney filtration 1.

Some key points to consider:

• Less than 1% of the administered maternal dose is excreted into breast milk, and of that, less than 1% is absorbed by the infant's gastrointestinal tract 1.
• The use of iodinated contrast is recommended only if essential, especially during pregnancy, but it does not necessitate stopping breastfeeding 1.
• It's essential to distinguish iodinated contrast from radioactive iodine compounds used in nuclear medicine, which do require temporary cessation of breastfeeding.
• If a mother remains concerned despite these reassurances, she may choose to express and discard breast milk for 24 hours after the procedure, though this precaution is not medically necessary.

Overall, the current evidence suggests that iodinated contrast agents can be safely used in breastfeeding mothers without interrupting breastfeeding, prioritizing the health and well-being of both the mother and the infant 1.

From the FDA Drug Label

There are no data on the presence of iodixanol in human milk, the effects on the breastfed infant or the effects on milk production. Iodinated contrast agents are poorly excreted into human milk and are poorly absorbed by the gastrointestinal tract of a breastfed infant The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for iodixanol and any potential adverse effects on the breastfed infant from iodixanol or from the underlying maternal condition Interruption of breastfeeding after exposure to iodinated contrast agents is not necessary because the potential exposure of the breastfed infant to iodine is small However, a lactating woman may consider interrupting breastfeeding and pumping and discarding breast milk for 10 hours (approximately 5 elimination half-lives) after iodixanol administration in order to minimize drug exposure to a breast fed infant.

Iodine contrast can cross into breast milk, but the amount is expected to be small due to poor excretion into human milk. It is poorly absorbed by the gastrointestinal tract of a breastfed infant.

• The FDA recommends considering the developmental and health benefits of breastfeeding along with the mother's clinical need for iodixanol and any potential adverse effects on the breastfed infant.
• Interruption of breastfeeding is not necessary, but a lactating woman may consider interrupting breastfeeding for 10 hours after iodixanol administration to minimize drug exposure to the breastfed infant 2.

From the Research

Iodine Contrast in Breast Milk

• Iodine contrast media can cross into breast milk, but only tiny amounts reach the milk 3
• The amount of iodinated contrast medium that enters the baby's gut is minimal and is considered to be a small potential risk 3
• There is no significant effect on the fetus or infant from the absorption of contrast medium, and it is not necessary to stop breastfeeding for 24 hours after receiving iodinated or gadolinium contrast agents 3

Safety for the Infant

• The use of iodinated contrast media in lactating women is considered safe, and the benefits of breastfeeding outweigh the potential risks 3
• Iodine is essential for infant health, and breast milk is an important source of iodine for breastfeeding infants 4, 5, 6, 7
• The iodine content of breast milk varies with dietary iodine intake, and adequate levels of iodine in breast milk are essential for optimal neonatal thyroid hormone stores and to prevent impaired neurological development in breast-fed neonates 6

Iodine Levels in Breast Milk

• The recommended adequate intake of iodine for infants is 110 microg/day for infants 0-6 months and 130 microg/day for infants 7-12 months 4
• Breast milk iodine concentrations vary widely between populations, but are highest in colostrum and decrease gradually throughout the lactation period 7
• Supplementation with high-dose or daily iodine during lactation can increase breast-milk iodine concentrations, and a dose-response relationship has been observed 7