Serial Free Bisphenol A and Bisphenol A Glucuronide Concentrations in Neonates

To determine the balance of metabolism of free bisphenol A (BPA) to the inactive conjugate, BPA glucuronide (BPAG), in neonates.

Free BPA and BPAG concentrations were measured in 78 urine samples collected between December 2012 and August 2013 from a cohort of 44 healthy full term (≥ 37 weeks' gestation) neonates at 2 intervals (3-6 days and 7-27 days of age). A questionnaire was administered at the time of sample collection. Neonates recruited into the study were born in an urban, tertiary care hospital.

Only BPAG was detected in the urine samples; concentrations ranged from <0.1 microg/L to 11.21 microg/L (median: 0.27 microg/L). Free BPA concentrations were below the limit of quantification of 0.1 microg/L. Age, but not sex or type of diet, was significantly associated with urinary BPAG concentration (P = .002).

Our results illustrate widespread BPA exposure in healthy full-term neonates and efficient conjugation of BPA to its readily excretable and biologically inactive form (BPAG) as early as 3 days of age. Factors other than type of diet may be important contributors to BPA exposure in neonates.