Levels of PCB congeners in maternal blood and their effect on maternal and neonatal thyroid hormones - result from Hokkaido study on environment and children’s health

抄録

Background: Reported evidence regarding relationships between PCBs at low exposure levels and thyroid homeostasis in adults and neonates has been considered contradictory.
Objectives: To investigate the relationship between maternal specific PCB congener levels and maternal and neonatal thyroid hormone (TH) levels.
Methods: We conducted a prospective cohort study of pregnant women from 2002 to 2005 in Sapporo, Japan. Maternal blood samples for measurement of PCBs were collected between 23 weeks of gestation and one week after delivery. Congener-specific analysis of PCBs was conducted using HRGC/HRMS. Maternal (n = 386) and infant (n = 411) blood samples for measurement of THs were obtained between 7 and 20 gestational weeks and between 4 and 7 days of age after birth, respectively. THs were measured by enzyme-linked immunosorbent assay as public screening program. Characteristics of mothers and their neonates were obtained from self-administered questionnaires and medical records.
Results: Maternal fT4 increased significantly with high non-ortho PCB concentrations. There were no significant associations among PCB levels and maternal TSH or neonatal TSH or fT4. Stratified analysis by neonatal gender showed no associations.