Effect of environmental exposure to cadmium on pregnancy outcome and fetal growth: a study on healthy pregnant women in China.

The objective of the present study was to evaluate the potential effect of environmental exposure to cadmium on pregnancy outcome and fetal growth. Normal pregnant women were selected from Da-ye city of Hubei province, a cadmium-polluted area, from November 2002 through January 2003. Whole blood of pregnant women, cord blood, and placenta were collected and cadmium levels were determined by inductively coupled plasma emission mass spectroscopy. Incidence rate of preterm labor (gestational age < or = 37 weeks) and neonatal asphyxia, neonatal birth height, and birth weight were compared between lower and higher cadmium exposure level groups. Whole blood cadmium of 44 mothers ranged from 0.80 to 25.20 microg/L. Cadmium concentration in maternal blood was significantly higher than that in cord blood (t = 11.44, P < 0.01). Placenta cadmium ranged from 0.084 to 3.97 microg/g dry weight. After adjustment for maternal age, history of gestation, abortion and lactation, Logistic regression analysis showed that there was no significant association between cadmium exposure levels and pregnancy outcome (premature labor or neonatal asphyxia). Multiple linear regression analysis showed that, cord blood cadmium level, but not maternal blood cadmium and placenta cadmium, was significantly negatively associated with neonatal birth height (t= -2.33, P < 0.05). Compared with lower cord blood cadmium level (< or = 0.40 microg/L), higher level of cord blood cadmium (>0.40 microg/L) was associated with 2.24cm decrease in neonatal birth height. There was no significant association between cadmium exposure and birth weight. It was concluded that environmental exposure to cadmium significantly lower neonatal birth height.