Maternal lead can be passed through breast milk to the baby. The benefits of breastfeeding likely outweigh the risks from potential exposure based on the current state of evidence. Lead cannot be removed from breast milk, but calcium supplementation (1,200 mg daily) has been associated with a 5–10% decrease in breast milk lead levels among individuals over the course of lactation. Encourage the initiation of breastfeeding at maternal BLL ≥ 40 μg/dL; however, the following steps should be taken:
- Evaluate potential lead exposure sources for both the lactating person and the infant. Provide guidance on eliminating additional lead sources and preventing further exposures.
- Prescribe calcium supplementation of 1,200 mg/daily.
- Monitor the infant with serial BLLs. Encourage the continuation of breastfeeding without interruption unless all the following are true:
- The infant’s BLL is ≥5 μg/dL.
- Maternal BLL is ≥20 μg/dL, and the infant’s BLL rises or fails to decline.
- A comprehensive evaluation of the infant’s diet and environment fails to identify any potential lead exposure sources other than breast milk.
Maternal BLL of ≥ 40μg/dL may result in more significant exposures to the infant, and it may be advisable to pump and discard breast milk until maternal BLL has decreased to less than 40 micrograms/dL. We recommend consulting with a PEHSU specialist or a clinician experienced in treating lead toxicity in lactating individuals before advising interruption of breastfeeding based on blood lead levels.