Blood manganese concentrations and intrauterine growth restriction.

To assess the relationship between blood concentrations of manganese (Mn) and intrauterine growth restriction (IUGR), Mn levels in the umbilical cord blood (UCB) and the mother whole blood (MWB) samples were measured in apparently healthy mothers and their newborns. Measurement was conducted by an inductively coupled plasma mass spectrometry. Manganese concentrations in MWB were significantly lower (p<0.01) in IUGR cases than in appropriate for gestational age (AGA) cases (mean+/-S.D.; 16.7+/-4.8 and 19.1+/-5.9 microg/l, respectively). Conversely, UCB concentrations of Mn were significantly higher (p<0.05) in IUGR newborns than AGA newborns (44.7+/-19.1 and 38.2+/-13.1 microg/l, respectively). Logistic regression analysis demonstrated significant relationships of the mother whole blood and the umbilical cord blood concentrations of Mn in IUGR cases (OR=0.868, 1.044, respectively). The study suggests that manganese concentrations in MWB and UCB might induce different effects on birth weight in healthy mothers. Because intrauterine growth restriction is a multi-factorial problem, further epidemiological and clinical studies on larger numbers of subjects are needed to confirm the findings in the present study.