Information in this record refers to the use of iodohippurate sodium I 123 (I 123 ortho-iodohippurate; I 123 OIH) as a kidney function diagnostic agent. However, some experts recommend nursing the infant just before administration of the radiopharmaceutical and interrupting breastfeeding for 8 to 12 hours after the dose.[1-3] This recommendation is based on possible contamination with other iodine isotopes, which no longer occurs, so a US Nuclear Regulatory Commission subcommittee has recommended that breastfeeding should be interrupted for only 4 hours after administration of I 123 OIH in doses up to 100 MBq (4 mCi) to a nursing mother.[4] If the mother has expressed and saved milk prior to the examination, she can feed it to the infant during the period of nursing interruption.[1,5] Mothers need not refrain from close contact with their infants after usual clinical doses.[6]
Mothers concerned about the level of radioactivity in their milk could ask to have it tested at a nuclear medicine facility at their hospital. When the radioactivity is at a safe level, she may resume breastfeeding. A method for measuring milk radioactivity and determining the time when a mother can safely resume breastfeeding has been published.[7]