| Rank* | County | Percent of Total Births to Women who Smoked during Pregnancy | County/State Ratio | County/US Ratio |
|---|---|---|---|---|
| 1 | Beaufort County | 6.0 | 0.50 | 0.49 |
| 2 | Richland County | 6.1 | 0.51 | 0.50 |
| 3 | Allendale County | 6.7 | 0.56 | 0.55 |
| 4 | Jasper County | 6.9 | 0.57 | 0.56 |
| 5 | Williamsburg County | 7.0 | 0.59 | 0.58 |
| 6 | Edgefield County | 7.1 | 0.60 | 0.59 |
| 7 | Georgetown County | 7.4 | 0.62 | 0.61 |
| 8 | Greenwood County | 7.7 | 0.64 | 0.63 |
| 9 | Charleston County | 7.7 | 0.65 | 0.63 |
| 10 | Lee County | 7.9 | 0.66 | 0.65 |
| 11 | Fairfield County | 8.6 | 0.71 | 0.70 |
| 12 | Hampton County | 8.9 | 0.74 | 0.73 |
| 13 | Saluda County | 9.1 | 0.76 | 0.75 |
| 14 | McCormick County | 9.1 | 0.76 | 0.75 |
| 15 | Clarendon County | 9.3 | 0.78 | 0.77 |
| 16 | Bamberg County | 10.2 | 0.85 | 0.83 |
| 17 | Sumter County | 10.5 | 0.88 | 0.86 |
| 18 | Florence County | 10.9 | 0.91 | 0.89 |
| 18 | Orangeburg County | 10.9 | 0.91 | 0.89 |
| 20 | Barnwell County | 11.3 | 0.95 | 0.93 |
| 21 | Greenville County | 11.6 | 0.97 | 0.95 |
| 22 | Calhoun County | 11.8 | 0.99 | 0.97 |
| 23 | Aiken County | 11.9 | 0.99 | 0.98 |
| 24 | Marion County | 12.7 | 1.06 | 1.04 |
| 25 | Darlington County | 12.9 | 1.08 | 1.06 |
| 26 | Newberry County | 13.1 | 1.10 | 1.08 |
| 27 | Dorchester County | 13.2 | 1.10 | 1.09 |
| 28 | Berkeley County | 13.3 | 1.11 | 1.09 |
| 29 | Abbeville County | 13.7 | 1.14 | 1.12 |
| 30 | Lexington County | 14.8 | 1.24 | 1.22 |
| 31 | Colleton County | 14.9 | 1.24 | 1.22 |
| 32 | Spartanburg County | 15.0 | 1.25 | 1.23 |
| 33 | Marlboro County | 15.1 | 1.26 | 1.24 |
| 34 | Anderson County | 15.7 | 1.31 | 1.29 |
| 35 | Kershaw County | 16.7 | 1.39 | 1.37 |
| 36 | Lancaster County | 16.9 | 1.41 | 1.39 |
| 36 | Laurens County | 16.9 | 1.41 | 1.39 |
| 38 | Dillon County | 17.1 | 1.43 | 1.41 |
| 39 | Chesterfield County | 17.3 | 1.44 | 1.42 |
| 39 | York County | 17.3 | 1.44 | 1.42 |
| 41 | Pickens County | 18.0 | 1.50 | 1.48 |
| 42 | Union County | 18.0 | 1.50 | 1.48 |
| 43 | Oconee County | 18.3 | 1.53 | 1.50 |
| 44 | Horry County | 18.9 | 1.57 | 1.55 |
| 45 | Chester County | 19.2 | 1.60 | 1.57 |
| 46 | Cherokee County | 23.3 | 1.94 | 1.91 |
* 1 is best, 46 is worst.