Multivariable conditional logistic regression analysis: discrimination between early and late onset*
| Odds ratio (95% CI) | p Value | |
| Group B streptococcus carrier | ||
| Yes | 6.85 (2.74 to 17.1) | <0.001 |
| No | ||
| Maternal infection | ||
| Yes | 3.87 (1.02 to 14.8) | 0.045 |
| No | ||
| Maximum intrapartum temperature | 2.13 per °C (1.15 to 3.93) | 0.01 |
| Duration of ruptured membranes | ||
| <18 h | 0.043 | |
| ⩾18 h | 1.93 (1.02 to 3.64) | |
| Fetal tachycardia | ||
| Yes | 1.86 (0.95 to 3.66) | 0.072 |
| No | ||
| No of vaginal examinations | ||
| Early onset | 1.10 per examination (0.96 to 1.26) | 0.019† |
| Late onset | 0.78 per examination (0.60 to 1.02) |
*Adjusted for age, categorised as younger or older than 20 years of age, maternal temperature >38°C and postdelivery antibiotics for mother.
†p Value of interaction.