Table 2. Serum concentrations of PFASs and PFAS precursors, associations and ratios between matched maternal and cord serum.
| PFHxS (ng/mL) | PFOS (ng/mL) | PFOA (ng/mL) | PFNA (ng/mL) | PFDA (ng/mL) | PFUnA (ng/mL) | PFDoA (ng/mL) | 6:2 FTS (pg/mL) | NMeFOSAA (pg/mL) | |
|---|---|---|---|---|---|---|---|---|---|
| Maternal serumab | |||||||||
| Percent > LOD | 100% | 100% | 100% | 100% | 100% | 99% | 68% | 82% | 74% |
| Mean ± SD | 0.63 ± 0.47 | 5.08 ± 3.26 | 1.95 ± 1.09 | 0.52 ± 0.27 | 0.45 ± 0.28 | 0.45 ± 0.24 | 0.046 ± 0.026 | 48.38 ± 40.94 | 4.77 ± 6.68 |
| Median | 0.50 | 4.41 | 1.64 | 0.46 | 0.37 | 0.40 | 0.041 | 41.44 | 3.40 |
| GM | 0.53 | 4.23 | 1.74 | 0.46 | 037 | 0.38 | 0.040 | 26.04 | 2.06 |
| Range | 0.12–4.22 | 0.73–19.96 | 0.73–8.11 | 0.13–1.69 | 0.038–2.07 | <LOD-1.27 | <LOD-0.15 | <LOD-203.00 | <LOD-46.79 |
| Cord serumab | |||||||||
| Percent > LOD | 100% | 100% | 100% | 100% | 100% | 96% | 33% | 90% | 66% |
| Mean ± SD | 0.26 ± 0.30 | 1.52 ± 1.01 | 1.32 ± 0.69 | 0.23 ± 0.12 | 0.13 ± 0.09 | 0.14 ± 0.10 | 0.028 ± 0.013 | 33.54 ± 38.52 | 1.58 ± 2.36 |
| Median | 0.18 | 1.18 | 1.15 | 0.20 | 0.10 | 0.12 | 0.021 | 24.68 | 0.67 |
| GM | 0.19 | 1.27 | 1.18 | 0.21 | 0.10 | 0.11 | 0.026 | 19.98 | 0.76 |
| Range | 0.014–3.17 | 0.24–6.93 | 0.40–5.06 | 0.05–0.80 | 0.024–0.61 | <LOD-0.75 | <LOD-0.082 | <LOD-252.12 | <LOD-16.00 |
| Maternal-fetal correlationc | r = 0.684 P < 0.001 | r = 0.626 P < 0.001 | r = 0.806 P < 0.001 | r = 0.704 P < 0.001 | r = 0.652 P < 0.001 | r = 0.630 P < 0.001 | r = 0.520 P < 0.001 | r = 0.336 P < 0.001 | r = 0.399 P < 0.001 |
| Maternal and cord serum concentration ratiod | |||||||||
| Mean CS ± SD:MS | 0.43 ± 0.34:1 | 0.36 ± 0.35:1 | 0.71 ± 0.22:1 | 0.49 ± 0.29:1 | 0.35 ± 0.44:1 | 0.36 ± 0.42:1 | 0.61 ± 0.34:1 | 3.08 ± 4.34:1 | 7.79 ± 11.14:1 |
| Median CS:MS | 0.35:1 | 0.29:1 | 0.65:1 | 0.43:1 | 0.25:1 | 0.27:1 | 0.51:1 | 1.66:1 | 3.83:1 |
LOD, limit of detection; SD, standard deviation; GM, geometric mean; CS, Cord Serum; MS, Maternal Serum. aUndetectable concentration was accounted as a value equal to the LOD divided by the square root of 2 and values below the LOQ were used unaltered. bData of other analyates were not reported due to the low frequency of detection in the samples (<30% in both maternal and cord serum samples). cSince concentrations of PFHxS, PFOS, PFOA, PFNA, PFDA and PFUnA were normally distributed after log-transformed, Pearson correlation test was used to test the log-transformed concentrations for possible correlations. Spearman correlation test was used to test the correlations of non-normally distributed PFDoA, 6:2 FTS and NMeFOSAA. dFor each compound, samples having undetectable concentration in both maternal and cord serum were excluded.