Early-life exposure to lithium in drinking water and infant thyroid function.

Abstract

Introduction: Elevated lithium exposure via drinking water seems to impair thyroid function in pregnant women, but potential impact on the infants is unknown. This study aimed at elucidating if elevated early-life lithium exposure may affect the infant thyroid function. Methods: In a population-based mother-child cohort recruited at early pregnancy in the Argentinean Andes, where drinking water lithium vary 5-1,660μg/L, we followed up the infants (n=110) up to 6 months of age. We assessed early-life lithium exposure by the concentrations in maternal blood (average concentrations during pregnancy), cord blood and infant urine at 0-3 and 3-6 months of age, measured by inductively coupled plasma mass spectrometry. Markers of infant thyroid function included thyrotropin (TSH), free/total thyroxine (fT4/T4) and free/total triiodothyronine (fT3/T3) in serum at 3-6 months of age. Results: The lithium concentration in cord blood (CB-Li), median 51μg/L (range 9.5-156), was higher than in maternal blood (B-Li), 27μ...