Table 5.

Summary of the results from clinical studies on infant lithium exposure through lactation

Study	Design	Sample size	Findings
Schou et al. (1973)	Case series	8 mother–infant pairs	Infant/maternal serum lithium concentration of 1/2 in first week and 1/3 during the following weeks
Sykes et al. (1976)	Case report	1 mother–infant pair	Breast milk lithium level of 1/4 of maternal serum level, infant had good excretion of lithium into urine
Moretti et al. (2003)	Case series	11 mother–infant pairs	Infant lithium dose of 0–30% of the maternal dose/kg Infant serum level of 17–50% of maternal serum level
Viguera et al. (2007a, b)	Case series	10 mother–infant pairs	Mean infant serum level of 0.16 meq/L (range 0.09–0.25) In four infants: transient elevations of TSH, blood urea nitrogen and creatinine
Bogen et al. (2012)	Case series	3 mothers with 4 infants	Infant lithium levels ranged from 10 to 17% of maternal levels at 1 month postpartum
Frew (2015)	Case report	1 mother–infant pair	Infant/maternal serum lithium concentration ratio of 0.58. No adverse events