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Family history of preterm birth among enrolled patients.
| Number of patients | Case definition |
|---|---|
| 15 | 3 generations of PTB |
| 57 | 2 generations of PTB |
| 12 | Generational skips |
| 6 | Intra-generational PTB |
| 32 | Same mother with multiple PTB |
| 68 | No personal or family history PTB |
