After conducting a literature review that yielded limited data, researchers found that a clinician’s recommendation on whether to continue lithium while breastfeeding must be personalized to the individual woman with bipolar disorder and her infant.
"This is a highly controversial topic, and expert recommendations vary, but the truth is it's 2019, and we still don't have the evidence to back up any of the fears about lithium use and breastfeeding," Crystal Clark, MD, MSc, assistant professor of psychiatry and behavioral sciences and obstetrics and gynecology at Northwestern University, said in a press release. "There are few absolutes when it comes to managing illness while breastfeeding. It's not one size fits all.”
The researchers systematically reviewed the available data on lithium and breastfeeding to determine the risk–benefit assessment of infant exposure to lithium through breast milk among women with bipolar disorder. They searched clinical online databases to include articles that reported infant-to-maternal serum lithium concentration ratios, infant serum-to-breast milk lithium concentration ratios, milk-to maternal serum (M/S) lithium concentration ratios and relative infant dose (RID).
The review included 12 articles, all case reports. Clark and colleagues found that the data were limited on the safety of lithium continuation while breastfeeding and that lithium transfer to the infant from breast milk was variable. Overall, three cases reported on adverse effects in infants exposed to lithium through breast milk; however, these infant health complications were typically confounded by other factors affecting infant health, concomitant medications and gestational lithium exposure, making it difficult for the investigators to differentiate poor outcomes.
“The lack of adverse effects in infants despite the infant-to-maternal serum lithium concentration ratios, infant serum-to-breast milk lithium concentration ratios, M/S ratios, or RID suggests that monitoring with labs for lithium, thyroid stimulating hormone, and blood urea nitrogen concentrations may only be necessary for any infant that presents with unusual behavior, restlessness, difficulty feeding, increased sedation, or abnormal growth or development,” Clark and colleagues explained in International Review of Psychiatry.
The researchers wrote that clinicians should personalize their recommendations on whether a patient should continue lithium while breastfeeding based on her and her baby.
“Clinicians must engage their patients in a risk–benefit discussion with attention to all available data on the outcomes of infant exposure to lithium through breast milk,” they wrote. “Future, more standardized research is necessary to better elucidate the extent of maternal–infant lithium transfer and the effects of breast milk exposure on infant health and development.” – by Savannah Demko
Disclosure: The authors report no relevant financial disclosures.