Contents of chemical elements in stomach during prenatal development: different age-dependent dynamical changes and their significance

Table 1 Contents of constant elements in fetal stomachs, with comparison to those in adult[2] (µg/g dry weight)

Age (mon)	4	5	6	7	8	9	10	Adult
K	7995.7	8148.9	8712.2	8583.1	8838.4	9091.5	8987.2	5193.7
	2309.1 (6)	2783.7 (19)	1969.6 (14)	1405.1 (9)	1731.5 (7)	2308.9 (6)	894.2 (5)	1457.7
Na	13237.5	11255.8	10708.8	9368.1	7859.1	9673.3	8023.6	4894.4
	1540.3 (6)	2096.0 (19)	2718.0 (14)	2112.5 (9)	2433.1 (7)	1855.6 (6)	1853.8 (5)	1626.8
Ca	972.7	676.1	704.5	662.6	699.4	575.5	518.8	89.7
	60.3 (6)	191.9 (19)	147.3 (14)	110.4 (9)	243.8 (7)	103.7 (6)	159.0 (5)	47.5
Mg	591.8	589.5	627.4	622.7	648.1	519.7	509.8	494.0
	203.3 (6)	155.6 (19)	99.6 (14)	91.9 (9)	71.5 (7)	96.5 (6)	84.6 (5)	159.7
P	7850.8	7668.5	7029.8	6213.7	6117.3	6216.3	6122.4
	2113.8 (6)	1092.0 (19)	969.1 (14)	946.3 (9)	752.4 (7)	722.9 (6)	312.9 (5)
Al	12.922	14.486	14.152	14.792	10.786	10.096	5.722
	8.947 (6)	5.794 (19)	8.620 (14)	8.608 (9)	4.513 (7)	7.342 (6)	5.208 (5)

Data in the upper row for each element is average mean, those in the lower is standard deviation with the case numbers in bracket. Case number of adult is 100.

Table 2 Contents of essential elements in fetal stomachs, with comparison to those in adult[2] (µg/g dry weight)

Month-age	4	5	6	7	8	9	10	Adult
Cu	47.33	37.26	38.98	37.67	38.28	27.65	32.20	4.95
	13.95 (6)	14.74 (19)	9.02 (14)	16.44 (9)	17.42 (7)	8.53 (6)	8.43 (5)	1.52
Zn	310.7	311.1	279.6	215.2	150.6	136.0	120.5	71.87
	38.8 (6)	124.6 (19)	50.3 (14)	44.7 (9)	81.2 (7)	34.9 (6)	12.6 (5)	15.42
Fe	765.1	677.0	550.9	503.1	559.8	530.1	534.3	138.6
	188.5 (6)	257.3 (19)	158.1 (14)	147.4 (9)	98.9 (7)	260.0 (6)	131.3 (5)	61.4
Mn	3.266	2.849	2.833	2.918	3.068	2.370	2.547	2.440
	0.797 (6)	0.881 (19)	1.015 (14)	0.934 (9)	0.859 (7)	0.387 (6)	0.512 (5)	1.116
Se	-	0.565	0.553	0.539	0.471	0.468	0.411
	0.042 (2)	0.186 (10)	0.161 (9)	0.240 (7)	0.089 (6)	0.137 (5)
Co	0.575	0.613	0.711	0.709	0.648	0.595	0.569	0.060
	0.380 (6)	0.292 (19)	0.320 (14)	0.547 (9)	0.259 (7)	0.229 (6)	0.188 (5)	0.377
Cr	0.595	0.565	0.513	0.510	0.359	0.302	0.325	3.958
	0.291 (6)	0.309 (19)	0.396 (14)	0.397 (9)	0.241 (7)	0.154 (6)	0.181 (5)	6.511
Ni	0.511	0.898	0.517	0.483	0.780	0.530	0.211	0.662
	0.254 (6)	1.551 (19)	0.584 (14)	0.302 (9)	0.293 (7)	0.426 (6)	0.096 (5)	0.556
Sr	1.231	0.785	0.922	0.735	0.651	0.374	0.564
	0.554 (6)	0.394 (19)	0.502 (14)	0.238 (9)	0.236 (7)	0.170 (6)	0.178 (5)
V	0.707	0.500	0.702	0.581	0.640	0.556	0.327
	0.521 (6)	0.386 (19)	0.524 (14)	0.170 (9)	0.261 (7)	0.413 (6)	0.173 (5)

Table 3 Contents of harmful elements in fetal stomachs, with comparison to those in adult[2] (µg/g dry weight)

Month-age	4	5	6	7	8	9	10	Adult
Li	0.707	0.720	0.699	0.653	0.567	0.479	0.383
	0.903 (6)	0.328 (19)	0.374 (14)	0.318 (9)	0.189 (7)	0.258 (6)	0.165 (5)
Cd	0.266	0.197	0.129	0.128	0.103	0.108	0.081	0.835
	0.357 (6)	0.189 (19)	0.080 (14)	0.070 (9)	0.065 (7)	0.053 (6)	0.039 (5)	0.553
Pb	1.091	0.882	0.881	0.851	0.879	0.884	0.835	0.426
	0.607 (6)	0.565 (19)	1.245 (14)	0.578 (9)	0.948 (7)	0.461 (6)	0.370 (5)	0.356
Ba	2.542	1.361	1.055	0.911	1.053	0.415	0.705
	1.214 (6)	0.789 (19)	0.447 (14)	0.770 (9)	1.445 (7)	0.183 (6)	0.228 (5)
Ti	0.347	0.567	0.474	0.497	0.543	0.533	0.419
	0.154 (6)	0.298 (19)	0.275 (14)	0.286 (9)	0.353 (7)	0.385 (6)	0.290 (5)

Table 4 Stomach weights of fetus aging from 4 to 10 months

Month-age	4	5	6	7	8	9	10
Weight (gram)	0.35	0.94	1.73	3.17	4.20	5.41	8.93
	0.12 (6)	0.45 (19)	0.64 (14)	0.74 (9)	1.19 (7)	0.76 (6)	2.10 (5)
Fixed ratio (%)	100	268.6	494.3	905.7	1200.0	1545.7	2551.4
Circular ratio (%)	-	268.6	184.0	183.2	132.5	128.8	165.1

The data in the upper row was average mean, that in the lower row was standard deviation, with the case number in bracket.

Fixed ratio = stomach weight of fetus age of i month/stomach weight of fetus age of i month× 100%;

Circular ratio = stomach weight of fetus age of j month/stomach weight of fetus age of i month× 100%;

(i = 4, 5...10; j = i + 1, j_max = 10)

Table 5 Relation between elements’ contents and age of fetus

Remarkable positive relativity (Pearson r)	Remarkable negative relativity (Pearson r)		Unobvious relativity (Pearson r)
K (0.9301)b	Na (-0.8815)b	Mn (-0.7364)a	Mg (-0.5265)
	Ca (-0.9222)b	Cr (-0.9515)b	Co (-0.1858)
	P (-0.7221)a	Sr (-0.8734)b	Ni (-0.4872)
	Al (-0.7983)a	Li (-0.9419)b	V (-0.6348)
	Cu (-0.8259)a	Cd (-0.9051)b	Pb (-0.0002)
	Zn (-0.9700)a	Ba (-0.8369)b	Ti (0.2161)
	Fe (-0.7883)a	Se (-0.9648)b

^aP < 0.05,

^bP < 0.01.