Table 2.
Association of centered and standardized tooth metals measured in second or third trimester with birth weight Z-score and gestational age at delivery. Bolded values highlight all P-values <0.05.
| Metal | Second trimester | Third trimester | Effect by time | ||||||
|---|---|---|---|---|---|---|---|---|---|
| β | 95% CI | P | β | 95% CI | P | β* | 95% CI | P | |
| Birth Weight Z-score | |||||||||
| Model 1 | |||||||||
| Mn | 0.21 | (0.05, 0.37) | 0.01 | 0.21 | (0.05, 0.37) | 0.01 | −0.02 | (−0.49, 0.45) | 0.92 |
| Pb | −0.20 | (−0.38, −0.02) | 0.02 | −0.13 | (−0.29, 0.03) | 0.12 | −0.34 | (−0.93, 0.25) | 0.26 |
| Zn | 0.12 | (−0.06, 0.30) | 0.16 | 0.12 | (−0.04, 0.28) | 0.16 | 0.14 | (−0.72, 1.00) | 0.76 |
| Model 2 | |||||||||
| Mn | 0.19 | (0.03, 0.35) | 0.02 | 0.16 | (0.00, 0.32) | 0.05 | 0.10 | (−0.35, 0.55) | 0.68 |
| Pb | −0.12 | (−0.32, 0.08) | 0.23 | −0.04 | (−0.22, 0.14) | 0.69 | −0.34 | (−0.93, 0.25) | 0.26 |
| Zn | 0.09 | (−0.07, 0.25) | 0.27 | 0.09 | (−0.07, 0.25) | 0.31 | 0.23 | (−0.61, 1.07) | 0.59 |
| Model 3 | |||||||||
| Mn | 0.17 | (0.01, 0.33) | 0.03 | 0.16 | (0.00, 0.32) | 0.05 | 0.03 | (−0.42, 0.48) | 0.89 |
| Pb | −0.15 | (−0.35, 0.05) | 0.12 | −0.06 | (−0.24, 0.12) | 0.53 | −0.31 | (−0.90, 0.28) | 0.30 |
| Zn | 0.07 | (−0.09, 0.23) | 0.39 | 0.07 | (−0.09, 0.23) | 0.42 | 0.16 | (−0.66, 0.98) | 0.70 |
| Gestational Age at Delivery | |||||||||
| Model 1 | |||||||||
| Mn | 0.03 | (−0.19, 0.25) | 0.80 | 0.01 | (−0.21, 0.23) | 0.90 | 0.05 | (−0.60, 0.70) | 0.87 |
| Pb | 0.01 | (−0.23, 0.25) | 0.96 | 0.08 | (−0.14, 0.30) | 0.48 | −0.27 | (−1.07, 0.53) | 0.51 |
| Zn | −0.05 | (−0.29, 0.19) | 0.66 | −0.04 | (−0.28, 0.20) | 0.72 | −0.22 | (−1.40, 0.96) | 0.71 |
| Model 2 | |||||||||
| Mn | 0.03 | (−0.19, 0.25) | 0.79 | 0.03 | (−0.21, 0.27) | 0.80 | 0.04 | (−0.61, 0.69) | 0.90 |
| Pb | 0.07 | (−0.20, 0.34) | 0.62 | 0.10 | (−0.14, 0.34) | 0.42 | −0.15 | (−0.97, 0.67) | 0.73 |
| Zn | −0.03 | (−0.27, 0.21) | 0.79 | −0.02 | (−0.26, 0.22) | 0.85 | −0.14 | (−1.32, 1.04) | 0.82 |
| Model 3 | |||||||||
| Mn | 0.02 | (−0.22, 0.26) | 0.86 | 0.00 | (−0.24, 0.24) | 1.00 | 0.11 | (−0.56, 0.78) | 0.76 |
| Pb | 0.08 | (−0.19, 0.35) | 0.55 | 0.14 | (−0.11, 0.39) | 0.26 | −0.22 | (−1.08, 0.64) | 0.61 |
| Zn | −0.03 | (−0.27, 0.21) | 0.83 | −0.01 | (−0.25, 0.23) | 0.92 | −0.11 | (−1.31, 1.09) | 0.86 |
*
β for the effect by time is the difference in effect estimates from the 2nd and 3rd trimesters
Mn, manganese; Pb, lead; Zn, Zinc; β, Beta; CI, Confidence Interval
Model 1: Adjusted for batch, tooth attrition, and tooth type
Model 2: Adjusted for batch, tooth attrition, tooth type, and race
Model 3: Adjusted for batch, tooth attrition, tooth type, race, urban, ETS, anemic, maternal age, and year house built