The Concentration of Micronutrients and Heavy Metals in Maternal Serum, Placenta, and Cord Blood: A Cross-Sectional Study in Preterm Birth

Table 3

Trace elements concentration of maternal serum, placenta, and cord blood. Placental concentration of all trace elements shows higher antioxidant concentration and lower concentration of mercury and lead, while only AtRA shows significant difference in maternal serum, as well as copper, selenium, and AtRA in cord blood.

Variable	Normal	Term (n = 25)	Preterm (n = 26)	P
Maternal serum
Manganese (μg/L)	≤ 1.1	1.00 (0.50 – 1.70)	1.09 (0.64)	0.428
Iron (μg/dL)	35 – 145	77.00 (24.00 – 221.00)	71.50 (22.00 – 234.00)	0.977
Copper (μg/dL)	75 – 145	222.65 (0 – 376.80)	215.35 (68.40 – 313.70)	0.655
Zinc (μg/dL)	60 – 130	45.16 (9.32)	40.26 (13.96)	0.116
Mercury (μg/L)	≤ 9	2.33 (1.49)	3.14 (2.19)	0.178
Lead (μg/dL)	≤ 9	3.25 (1.50 – 7.60)	2.81 (1.21)	0.177
Selenium (μg/L)	23 - 190	76.42 (16.30)	72.77 (18.04)	0.458
AtRA (ng/mL)		0.22 (0.07)	0.12 (0.03)	<0.001
25(OH)D (ng/mL)	30 - 44	15.42 (5.67)	14.00 (3 – 53)	0.760
Placenta
Manganese (μg/g)		0.99 (0.38 – 1.78)	0.42 (0.18)	<0.001
Iron (μg/g)		252.16 (170.61)	78.45 (51.73)	<0.001
Copper (μg/g)		2.96 (1.80)	1.62 (0.70 – 3.88)	0.019
Zinc (μg/g)		58.34 (27.88 – 124.05)	28.41 (1.46 – 137.69)	0.011
Mercury (ng/g)		0.20 (0.17)	20.47 (41.35)	0.019
Lead (ng/g)		0.02 (0.01)	0.81 (1.43)	0.009
Selenium (ng/g)		0.31 (0.31)	0.14 (0.20)	0.024
AtRA (ng/g)		21.7 (10.69)	0.7 (0.42 – 5.10)	<0.001
25(OH)D (ng/g)		75.84 (45.12)	18.00 (5 – 88)	<0.001
Cord blood
Manganese (μg/L)		3.40 (2.10 – 19.40)	3.19 (1.08)	0.327
Iron (μg/dL)		212.00 (111.00 – 1324.00)	236.50 (131.00 – 803.00)	0.380
Copper (μg/dL)		32.20 (16.30 – 69.60)	20.60 (5.80 – 53.30)	0.006
Zinc (μg/dL)		293.80 (234.59)	321.43 (176.59)	0.210
Mercury (μg/L)		3.50 (0.90 – 12.00)	4.63 (2.54)	0.461
Lead (μg/dL)		2.35 (0.80 – 5.70)	1.90 (0.70 – 3.80)	0.244
Selenium (μg/L)		49.65 (12.71)	41.83 (9.48)	0.021
AtRA (ng/mL)		0.16 (0.04)	0.07 (0.01)	<0.001
25(OH)D (ng/mL)		13.10 (6.25)	12.56 (5.17)	0.731

Mann-Whitney test. Independent t-test.