| Group Variables | Control (n = 42) | Study (n = 42) | ||
| PTB (<37 GW) | <34 GW | Number | 0 | 4 (9.4%) |
| Duration | 0 | 32.9 ± 0.14 | ||
| >34 - <37 GW | Number | 3 (7.1%) | 9 (21.4%)* | |
| Duration | 35 ± 0.6 | 35.75 ± 0.7 | ||
| Total | Number | 3 (7.1%) | 13 (31%)* | |
| Duration | 35 ± 0.6 | 35 ± 1.5 | ||
| >37 GW | Number | 39 (92.9%) | 29 (69%) | |
| Duration | 39.1 ± 0.8 | 38.4 ± 0.56 | ||
| Total | 38.8 ± 1.3 | 37.2 ± 1.8* | ||