Table 2.
Persistent organic pollutants (POPs) in maternal serum according to pre-pregnancy use of combined oral contraceptives (COCs) and age. Data are presented as GM (95% CI), pg/ml. Levels below LOQ replaced with LOQ/2
| Chemical (n = 818) |
LOQ (pg/mL) |
n (%) > LOQ | Total Cohort (n = 818) | < 29 years old | p-value* | ≥ 29 years old | p-value* | ||
|---|---|---|---|---|---|---|---|---|---|
| Non-COC user (n = 164) | COC user (n = 173) | Non-COC user (n = 280) | COC user (n = 201) | ||||||
| PeCB | 10 | 0 | – | – | – | – | – | – | – |
| HCBa | 10 | 818 (100.0) | 45.12 (44.15–46.12) | 39.53 (37.65–41.51) | 43.79 (42.02–45.64) | 0.002 | 46.93 (45.16–48.76) | 48.84 (46.84–50.93) | 0.08 |
| α-HCH | 20 | 1 (0.1) | 10.03 (9.97–10.09) | – | 10.14 (9.86–10.43) | – | – | – | – |
| β-HCH | 15 | 315 (38.5) | 11.53 (11.05–12.03) | 9.97 (9.19–10.82) | 10.18 (9.23–11.22) | 0.89 | 12.42 (11.54–13.38) | 13.04 (12–14.17) | 0.25 |
| γ-HCH | 20 | 0 | – | – | – | – | – | – | – |
| Oxychlordane | 25 | 3 (0.4) | 12.55 (12.49–12.6) | 12.62 (12.39–12.86) | 12.5 (12.5–12.5) | 0.31 | 12.56 (12.48–12.65) | 12.5 (12.5–12.5) | 0.23 |
| Transnonachlora | 5 | 660 (80.7) | 7.63 (7.28–7.99) | 5.22 (4.69–5.81) | 6.22 (5.68–6.81) | 0.007 | 9.33 (8.69–10.01) | 9.36 (8.56–10.24) | 0.75 |
| p,p’-DDT | 15 | 49 (6.0) | 8.15 (3.96–16.78) | 8.04 (7.63–8.48) | 7.98 (7.55–8.43) | 0.52 | 8.27 (7.92–8.64) | 8.22 (7.8–8.67) | 0.80 |
| p,p’-DDEa | 40 | 816 (99.8) | 184.68 (176.15–193.63) | 152.19 (136.16–170.11) | 172.73 (155.62–191.72) | 0.03 | 198.45 (183.23–214.93) | 207.26 (190.11–225.96) | 0.33 |
| PCB 74a | 5 | 605 (74.0) | 6.29 (6–6.59) | 4.76 (4.28–5.3) | 5.58 (5.06–6.15) | 0.03 | 6.99 (6.5–7.52) | 7.55 (6.89–8.27) | 0.40 |
| PCB 99a | 5 | 665 (81.3) | 7.27 (6.97–7.59) | 5.59 (5.08–6.15) | 6.6 (6.04–7.22) | 0.01 | 8.09 (7.54–8.68) | 8.45 (7.78–9.18) | 0.58 |
| PCB 118a | 5 | 813 (99.4) | 16.15 (15.61–16.72) | 12.41 (11.54–13.35) | 14.2 (13.23–15.24) | 0.004 | 18.27 (17.28–19.32) | 18.85 (17.68–20.1) | 0.59 |
| PCB 138a | 5 | 818 (100.0) | 72.01 (69.66–74.43) | 56.67 (52.73–60.9) | 64.81 (60.36–69.6) | 0.02 | 80.98 (76.7–85.5) | 81.4 (76.71–86.38) | 0.93 |
| PCB 153a | 5 | 818 (100.0) | 108.98 (105.4–112.68) | 84.45 (78.45–90.92) | 96.08 (89.38–103.29) | 0.02 | 124.74 (118.26–131.59) | 123.88 (116.85–131.33) | 0.86 |
| PCB 156a | 5 | 739 (90.3) | 10.97 (10.49–11.48) | 7.91 (7.11–8.81) | 9.19 (8.27–10.2) | 0.03 | 13.32 (12.45–14.25) | 12.74 (11.84–13.72) | 0.49 |
| PCB 170a | 5 | 818 (100.0) | 39.48 (38.04–40.97) | 30.15 (27.74–32.77) | 33.38 (30.74–36.26) | 0.055 | 47.01 (44.39–49.79) | 44.55 (41.82–47.46) | 0.38 |
| PCB 180a | 5 | 818 (100.0) | 75.3 (72.58–78.12) | 56.73 (52.16–61.7) | 62.28 (57.45–67.51) | 0.08 | 91.3 (86.3–96.58) | 85.41 (80.37–90.77) | 0.20 |
| PCB 183a | 5 | 620 (75.8) | 6.8 (6.5–7.12) | 4.79 (4.35–5.28) | 5.78 (5.27–6.35) | 0.02 | 8.31 (7.72–8.95) | 7.86 (7.21–8.56) | 0.31 |
| PCB 187a | 5 | 802 (98.0) | 17.76 (17.06–18.5) | 13.07 (11.88–14.37) | 14.53 (13.24–15.96) | 0.07 | 21.97 (20.71–23.31) | 20.17 (18.88–21.54) | 0.06 |
| PBDE 47 | 15 | 40 (5.0) | 8.01 (7.84–8.19) | 7.8 (7.55–8.05) | 8.26 (7.78–8.77) | 0.24 | 8 (7.69–8.32) | 7.99 (7.66–8.33) | 0.99 |
| PBDE 99 | 15 | 10 (1.2) | 7.62 (7.54–7.69) | 7.5 (7.5–7.5) | 7.72 (7.5–7.96) | 0.05 | 7.57 (7.47–7.68) | 7.69 (7.5–7.88) | 0.21 |
| PBDE 153 | 15 | 17 (2.1) | 7.76 (4.64–12.98) | 7.54 (7.47–7.61) | 7.89 (7.59–8.2) | 0.04 | 7.91 (7.59–8.24) | 7.62 (7.39–7.86) | 0.06 |
aChemicals detected in more than 70% of the samples above the LOQ were included in further analyses
*Based on Wilcoxon rank sum test
Abbreviations: CI confidence interval, GM geometric mean, LOQ limit of quantification, PeCB pentachlorobenzene, HCB hexachlorobenzene, HCH hexachlorocyclohexane, p,p´-DDT dichlorodiphenyltrichloroethane, p,p´-DDE dichlorodiphenyldichloroethylene, PCB polychlorinated biphenyls, PBDE polybrominated diphenyl ether