Table 3.
Serum concentration distributions of select biochemical indicators for pregnant Peruvian women1
| Biochemical indicator1 | LOD2 |
Trimesters 1–3 Combined |
Cord serum |
p-values4 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| % of samples below LOD | n | GM (95% CI)3 | Median (range) | Min. | Max. | % of samples below LOD | n | GM (95% CI) | Median | Min. | Max. | |||
| Retinol |
0.035 |
0.0 |
193 |
1.43 (1.40-1.49) |
1.46 |
0.74 |
2.63 |
0.0 |
52 |
0.64 (0.60-0.69) |
0.66 |
0.34 |
1.29 |
≤ 0.0001 |
| Retinyl palmitate |
0.025 |
65.3 |
193 |
NC5 |
LOD |
LOD |
0.11 |
100.0 |
52 |
NC |
NC |
LOD |
LOD |
NC |
| Retinyl stearate |
0.013 |
97.4 |
193 |
NC |
LOD |
LOD |
0.027 |
100.0 |
52 |
NC |
NC |
LOD |
LOD |
NC |
| Alpha-tocopherol |
0.94 |
0.0 |
193 |
27.2 (26.2-28.3) |
27.9 |
14.3 |
46.0 |
0.0 |
52 |
5.92 (5.52-6.35) |
5.80 |
3.60 |
15.5 |
≤ 0.0001 |
| Gamma-tocopherol |
0.26 |
0.0 |
193 |
3.14 (2.98-3.32) |
3.21 |
1.10 |
7.68 |
17.3 |
52 |
0.35 (0.31-0.39) |
0.34 |
0.18 |
0.98 |
≤ 0.0001 |
| Alpha-carotene |
0.013 |
0.0 |
193 |
0.19 (0.18-0.21) |
0.19 |
0.042 |
1.14 |
65.4 |
52 |
NC |
NC |
LOD |
0.007 |
NC |
| Beta-carotene |
0.015 |
0.0 |
193 |
0.21 (0.20-0.23) |
0.21 |
0.050 |
1.90 |
69.2 |
52 |
NC |
NC |
LOD |
0.005 |
NC |
| Cis-beta-carotene6 |
0.013 |
23.9 |
71 |
0.018 (0.017-0.020) |
0.017 |
0.009 |
0.12 |
100.0 |
31 |
NC |
NC |
LOD |
LOD |
NC |
| Beta-cryptoxanthin |
0.016 |
0.0 |
193 |
0.43 (0.39-0.47) |
0.45 |
0.07 |
2.39 |
0.0 |
52 |
0.052 (0.045-0.063) |
0.051 |
0.018 |
0.26 |
≤ 0.0001 |
| Lutein + zeaxanthin |
0.042 |
0.0 |
193 |
0.53 (0.50-0.58) |
0.53 |
0.11 |
1.24 |
0.0 |
52 |
0.11 (0.10-0.12) |
0.10 |
0.065 |
0.28 |
≤ 0.0001 |
| Trans-lycopene |
0.015 |
0.5 |
193 |
0.058 (0.052-0.063) |
0.054 |
0.011 |
0.53 |
100.0 |
52 |
NC |
NC |
LOD |
LOD |
NC |
| Total lycopene |
0.019 |
0.0 |
193 |
0.15 (0.14-0.18) |
0.15 |
0.028 |
1.04 |
94.2 |
52 |
NC |
NC |
LOD |
0.050 |
NC |
| Ferritin7 |
6.81 |
0.0 |
192 |
52.1 (45.2-60.2) |
52.8 |
6.74 |
528 |
0.0 |
47 |
321 (272–377) |
315 |
101 |
1090 |
≤ 0.0001 |
| Iron |
0.90 |
0.0 |
202 |
12.1 (11.2-13.0) |
12.8 |
2.33 |
30.6 |
0.0 |
47 |
26.2 (24.4-28.2) |
26.9 |
12.0 |
36.2 |
≤ 0.0001 |
| Unbound iron capacity |
1.80 |
0.0 |
182 |
55.6 (52.9-58.4) |
56.9 |
24.2 |
128 |
0.0 |
42 |
10.0 (8.09-12.6) |
10.4 |
1.79 |
31.7 |
≤ 0.0001 |
| Total iron bound capacity8 |
N/A |
0.0 |
181 |
71.3 (69.0-71.3) |
70.0 |
34.7 |
134 |
0.0 |
42 |
38.2 (36.2-40.3) |
37.5 |
25.1 |
57.7 |
≤ 0.0001 |
| Transferrin saturation9 |
N/A |
0.0 |
181 |
17.9 (16.4–19.6) |
19.0 |
3.0 |
53.0 |
0.0 |
42 |
67.0 (61.7–72.6) |
73.5 |
34.0 |
95.0 |
≤ 0.0001 |
| Selenium | 0.063 | 0.0 | 204 | 1.44 (1.41-1.44) | 1.46 | 0.79 | 2.15 | 0.0 | 44 | 0.86 (0.83-0.89) | 0.87 | 0.61 | 1.14 | ≤ 0.0001 |
1All values expressed in μmol/L unless otherwise noted.
2LOD limit of detection.
3GM geometric means; 95% CI = 95% confidence interval.
4p-values are based on a t-test and compare trimesters 1–3 combined with cord serum.
5NC not calculated. No calculations were conducted on samples for which 40% or more of the values were < LOD as per CDC methodology guidelines (17). For all other samples < LOD, calculations were based upon the LOD values divided by the square root of two.
6Because of laboratory quality control issues, the total sample size for CBC is lower compared with the remaining biochemical indicators.
7Values expressed in pmol/L (1 pmol/L = 2.247 ng/ml).
8TIBC total iron-binding capacity. TIBC = IRN + UIBC.
9Transferrin saturation = IRN/TIBC. Values expressed in %. TS does not have a specified LOD.