Table 3. Crude and adjusted1 associations between UGD-activity and adverse birth outcomes, among 156,697 women with a birth or fetal death in the 24-county Barnett Shale area, Texas, Nov. 30, 2010—Nov. 29, 2012.
| IDW Sum of UGD Well Activity | No. | Cases | Median (IQR) Wells | Crude OR (95% CI) | Adjusted OR (95% CI) |
|---|---|---|---|---|---|
| ½ Mile Buffer | |||||
| Preterm Birth2 | |||||
| 0 Wells ≤10 mi | 37,885 | 3,183 | Reference | ||
| 1st Tertile | 8,161 | 682 | 1 (1–2) | 0.99 (0.91, 1.08) | 1.18 (1.08, 1.29) |
| 2nd Tertile | 8,412 | 717 | 4 (3–5) | 1.02 (0.93, 1.11) | 1.21 (1.09, 1.33) |
| 3rd Tertile | 8,144 | 654 | 7 (5–10) | 0.95 (0.87, 1.04) | 1.14 (1.03, 1.25) |
| SGA3 | |||||
| 0 Wells ≤10 mi | 37,882 | 5,361 | Reference | ||
| 1st Tertile | 8,161 | 964 | 1 (1–2) | 0.81 (0.75, 0.87) | 0.95 (0.89, 1.00) |
| 2nd Tertile | 8,409 | 1,063 | 4 (3–5) | 0.88 (0.82, 0.94) | 1.01 (0.96, 1.06) |
| 3rd Tertile | 8,142 | 1,013 | 7 (5–10) | 0.86 (0.80, 0.93) | 1.01 (0.96, 1.06) |
| Fetal Death4 | |||||
| 0 Wells ≤10 mi | 38,029 | 147 | Reference | ||
| 1st Tertile | 8,188 | 27 | 1 (1–2) | 0.85 (0.57, 1.29) | 1.07 (0.69, 1.65) |
| 2nd Tertile | 8,438 | 29 | 4 (3–5) | 0.89 (0.60, 1.32) | 1.10 (0.72, 1.71) |
| 3rd Tertile | 8,174 | 32 | 7 (5–10) | 1.01 (0.69, 1.49) | 1.27 (0.82, 1.97) |
| 2 Mile Buffer | |||||
| Preterm Birth2 | |||||
| 0 Wells ≤10 mi | 37,885 | 3,183 | Reference | ||
| 1st Tertile | 23,231 | 1,856 | 7 (3–13) | 0.95 (0.89, 1.01) | 1.11 (1.04, 1.19) |
| 2nd Tertile | 23,758 | 2,006 | 32 (23–42) | 1.01 (0.95, 1.07) | 1.16 (1.09, 1.24) |
| 3rd Tertile | 23,227 | 1,921 | 54 (39–75) | 0.98 (0.93, 1.04) | 1.14 (1.07, 1.22) |
| SGA3 | |||||
| 0 Wells ≤10 mi | 37,882 | 5,361 | Reference | ||
| 1st Tertile | 23,227 | 2,785 | 7 (3–13) | 0.83 (0.79, 0.87) | 0.95 (0.90, 1.00) |
| 2nd Tertile | 23,757 | 2,984 | 32 (23–42) | 0.87 (0.83, 0.91) | 0.96 (0.91, 1.01) |
| 3rd Tertile | 23,223 | 2,847 | 54 (39–75) | 0.85 (0.81, 0.89) | 0.95 (0.90, 1.00) |
| Fetal Death4 | |||||
| 0 Wells ≤10 mi | 38,029 | 147 | Reference | ||
| 1st Tertile | 23,301 | 74 | 7 (3–13) | 0.82 (0.62, 1.09) | 1.14 (0.83, 1.56) |
| 2nd Tertile | 23,860 | 103 | 32 (23–42) | 1.12 (0.87, 1.44) | 1.56 (1.16, 2.11) |
| 3rd Tertile | 23,300 | 77 | 54 (39–75) | 0.85 (0.65, 1.13) | 1.16 (0.86, 1.58) |
| 10 Mile Buffer | |||||
| Preterm Birth2 | |||||
| 0 Wells ≤10 mi | 37,885 | 3,183 | Reference | ||
| 1st Tertile | 39,169 | 3,140 | 10 (1–67) | 0.95 (0.90, 1.00) | 1.02 (0.96, 1.08) |
| 2nd Tertile | 40,143 | 3,296 | 418 (267–748) | 0.98 (0.93, 1.03) | 1.13 (1.06, 1.20) |
| 3rd Tertile | 38,922 | 3,253 | 1190 (923–1489) | 0.99 (0.95, 1.05) | 1.15 (1.08, 1.22) |
| SGA3 | |||||
| 0 Wells ≤10 mi | 37,882 | 5,361 | Reference | ||
| 1st Tertile | 39,168 | 5,233 | 10 (1–67) | 0.94 (0.90, 0.98) | 1.03 (0.98, 1.08) |
| 2nd Tertile | 40,139 | 4,924 | 418 (267–748) | 0.85 (0.81, 0.88) | 0.95 (0.91, 1.00) |
| 3rd Tertile | 38,917 | 4,877 | 1190 (923–1489) | 0.87 (0.83, 0.91) | 0.96 (0.92, 1.01) |
| Fetal Death4 | |||||
| 0 Wells ≤10 mi | 38,029 | 147 | Reference | ||
| 1st Tertile | 39,325 | 157 | 10 (1–67) | 1.03 (0.83, 1.29) | 1.26 (0.99, 1.60) |
| 2nd Tertile | 40,277 | 138 | 418 (267–747) | 0.89 (0.70, 1.12) | 1.22 (0.95, 1.57) |
| 3rd Tertile | 39,066 | 149 | 1190 (923–1490) | 0.99 (0.79, 1.24) | 1.34 (1.04, 1.72) |
UGD: unconventional gas development; IDW: inverse distance weighted; IQR: interquartile range; OR: odds ratio; CI: confidence interval; mi: miles.
1All models adjusted for maternal age at delivery, pre-pregnancy BMI, race/ethnicity, education, smoking, adequacy of prenatal care utilization, and infant sex.
2Preterm Birth models additionally adjusted for previous poor pregnancy outcome; n = 156,119 because fetal deaths are excluded.
3SGA models additionally adjusted for parity; n = 156,106 because fetal deaths excluded.
4Fetal death models additionally adjusted for parity and previous poor pregnancy outcome.