Table 5.
Comparisons of maternal urinary concentrations of free and conjugated TCS (reported as μg TCS equivalents/L) at the various parity groups with respect to different levels of specific gravity (SG).
| Chemical | Parity | P25 of SGa | P50 of SGb | P75 of SGc | |||
|---|---|---|---|---|---|---|---|
| Differences | Adjusted GM (95% CI) | Differences | Adjusted GM (95% CI) | Differences | Adjusted GM (95% CI) | ||
| TCSGd | 0 | — | 6.25 (5.13, 7.60) | — | 12.30 (10.60, 14.28) | A | 27.13 (22.20, 33.14) |
| 1 | — | 6.98 (5.64, 8.63) | — | 10.93 (9.33, 12.80) | B | 18.43 (15.22, 22.32) | |
| ≥ 2 | — | 5.15 (3.61, 7.35) | — | 9.53 (7.35, 12.37) | AB | 19.53 (14.30, 26.67) | |
| Free TCSe | 0 | — | 0.02 (0.01, 0.02) | — | 0.06 (0.05, 0.07) | A | 0.26 (0.20, 0.33) |
| 1 | — | 0.02 (0.02, 0.03) | — | 0.05 (0.04, 0.06) | B | 0.15 (0.12, 0.19) | |
| ≥ 2 | — | 0.02 (0.01, 0.02) | — | 0.04 (0.03, 0.06) | B | 0.16 (0.11, 0.23) | |
| a25th percentile of SG = 1.007. b50th percentile of SG = 1.013. b75th percentile of SG = 1.020. dANCOVA model, assuming separate slopes for each of the parity groups because the interaction between parity and SG was significant (p < 0.05). Pairwise comparisons were made only when the overall difference between the parity groups was significant at that level of SG. Therefore, where no pairwise comparisons were made, the parity groups were not significantly different. eANCOVA model based on the ranks of the data (nonparametric model), assuming separate slopes for each of the parity groups because the interaction between parity and SG was significant (p < 0.05). Pairwise comparisons were made only when the overall difference between the parity groups was significant at that level of SG. Therefore, where no pairwise comparisons were made, the parity groups were not significantly different. | |||||||