| n | Mean (SD) | n | Mean (SD) | n | Mean (SD) | n | % | P values | |
| Birth weight (g) | 640 | 3167.6 (580.6) | 3950 | 3183.1 (556.3) | 4590 | 3180.9 (559.7) | 1 | 0.0 | 0.919 |
| Gestation to last completed week | 640 | 39.2 (2.2) | 3951 | 39.2 (1.9) | 4591 | 39.2 (1.9) | 0 | 0.0 | 0.516 |
| Maternal outcomes | |||||||||
| Pre-eclampsia | 19 | 3.0 | 146 | 3.7 | 165 | 3.6 | 0 | 0.0 | 0.36 |
| Gestational diabetes | 13 | 2.0 | 264 | 6.7 | 277 | 6.0 | 0 | 0.0 | <0.001 |
| Caesarean delivery | 93 | 14.5 | 990 | 25.1 | 1083 | 23.6 | 0 | 0.0 | <0.001 |
| Instrumental birth* | 78 | 14.3 | 706 | 23.9 | 784 | 22.4 | 5 | 0.1 | <0.001 |
*Vaginal deliveries only, included both forceps and ventouse deliveries.