Correlation of Maternal Blood Levels of Nickel and Arsenic with Fetal Growth and Development in the Second Trimester

Objective To investigate the living environment of pregnant women and the influence of maternal blood levels of nickel (Ni) and arsenic (As) on fetal growth and development, and to provide a basis for clarifying the influence of Ni and As on fetal growth and development.

Methods A heavy metal-contaminated area in Gansu province, China and its adjacent area located upwind the contaminated areas were selected as study areas(Ni and As concentration in ambient PM_2.5 at the contaminated area was higher than that at the control area), and a questionnaire survey was used to collect the basic information of pregnant women. Ultrasound was performed to measure biparietal diameter, head circumference, femur length, abdominal circumference, and fetal heart rate, and inductively coupled plasma-mass spectrometry was used to measure the levels of Ni and As in the venous blood of pregnant women in the second trimester. With the medians of blood Ni and As levels in 82 subjects in the control and contaminated areas as the cut-off values, the pregnant women and intrauterine fetuses were divided into low and high metal exposure groups according to the levels of Ni and As in the venous blood of pregnant women.

Results Compared with the low As exposure group, the high As exposure group had a significantly higher proportion of pregnant women from the contaminated area (χ²=14.07, P < 0.01). Compared with the low Ni exposure group, the high Ni exposure group had significantly lower median head circumference (201 mm vs 210 mm, Z=-2.53, P < 0.05) and median abdominal circumference (168 mm vs 182 mm, Z=-3.25, P < 0.05); compared with the low As exposure group, the high As exposure group had significantly lower median head circumference (204 mm vs 210 mm, Z=-2.03, P < 0.05) and median femur length (38 mm vs 39 mm, Z=-2.18, P < 0.05). Fetal head circumference and abdominal circumference were negatively correlated with the level of Ni in the venous blood of pregnant women (t=-4.76 and -5.45, P < 0.05).

Conclusion Exposure to atmosphere with Ni and As pollution in pregnant women may affect the intrauterine fetal growth and development, and the level of Ni in the venous blood of pregnant women in the second trimester is negatively correlated with fetal head circumference and abdominal circumference.