| County Number | County | % of babies born to young adult mothers w/low birthweight, 1990-99 | County / State Ratio |
|---|---|---|---|
| 1 | Pickens County | 6.9 | 0.76 |
| 2 | Beaufort County | 7.3 | 0.80 |
| 3 | Berkeley County | 7.3 | 0.80 |
| 4 | Oconee County | 7.3 | 0.80 |
| 5 | Dorchester County | 7.4 | 0.81 |
| 6 | Lexington County | 7.6 | 0.84 |
| 7 | Anderson County | 7.9 | 0.87 |
| 8 | Laurens County | 8.0 | 0.88 |
| 9 | York County | 8.0 | 0.88 |
| 10 | Edgefield County | 8.2 | 0.90 |
| 11 | Greenville County | 8.2 | 0.90 |
| 12 | Horry County | 8.2 | 0.90 |
| 13 | Jasper County | 8.3 | 0.91 |
| 14 | Hampton County | 8.6 | 0.95 |
| 15 | Saluda County | 8.6 | 0.95 |
| 16 | Kershaw County | 8.7 | 0.96 |
| 17 | Aiken County | 8.8 | 0.97 |
| 18 | Spartanburg County | 8.8 | 0.97 |
| 19 | Sumter County | 8.8 | 0.97 |
| 20 | Cherokee County | 8.9 | 0.98 |
| 21 | Colleton County | 9.0 | 0.99 |
| 22 | Chester County | 9.2 | 1.01 |
| 23 | Charleston County | 9.4 | 1.03 |
| 24 | Union County | 9.5 | 1.04 |
| 25 | Dillon County | 9.7 | 1.07 |
| 26 | Bamberg County | 9.8 | 1.08 |
| 27 | Greenwood County | 10.0 | 1.10 |
| 28 | Newberry County | 10.0 | 1.10 |
| 29 | Fairfield County | 10.1 | 1.11 |
| 30 | Clarendon County | 10.2 | 1.12 |
| 31 | Abbeville County | 10.3 | 1.13 |
| 32 | Chesterfield County | 10.5 | 1.15 |
| 33 | Georgetown County | 10.5 | 1.15 |
| 34 | Lancaster County | 10.5 | 1.15 |
| 35 | McCormick County | 10.6 | 1.16 |
| 36 | Richland County | 10.6 | 1.16 |
| 37 | Marion County | 10.7 | 1.18 |
| 38 | Calhoun County | 10.8 | 1.19 |
| 39 | Barnwell County | 10.9 | 1.20 |
| 40 | Marlboro County | 10.9 | 1.20 |
| 41 | Allendale County | 11.3 | 1.24 |
| 42 | Darlington County | 11.6 | 1.27 |
| 43 | Orangeburg County | 11.6 | 1.27 |
| 44 | Florence County | 11.7 | 1.29 |
| 45 | Lee County | 12.5 | 1.37 |
| 46 | Williamsburg County | 13.1 | 1.44 |
| 47 | South Carolina | 9.1 |