Table 3.

Multivariate logistic regression of potential predictors of intra-amniotic infection and imminent spontaneous preterm delivery^a

Predictors	Odds ratios	95% Confidence interval	P-value
Intra-amniotic infection
Early gestational age at sampling (≤ 29.0 weeks)	3.212	0.909–11.354	0.070
Very high serum CRP level (≥ 11.2 mg/L)	3.459	0.937–12.770	0.063
High plasma interleukin-6 level (≥ 4.8 pg/mL)	4.573	1.184–17.661	0.027
Short cervical length (≤ 20.6 mm)	2.492	0.733–8.472	0.144
Imminent preterm delivery
Older age (≥ 33 years)	1.841	0.593–5.716	0.291
Multiparity	3.888	1.242–12.175	0.020
High serum CRP level (≥ 3.5 mg/L)	5.275	1.145–24.299	0.033
High plasma interleukin-6 level (≥ 4.8 pg/mL)	6.515	2.114–20.078	0.001
Short cervical length (≤ 20.0 mm)	8.334	2.591–26.812	< 0.001

CRP C-reactive protein

^aAll continuous predictors were entered as dichotomous variables using the cut-off values derived from the receiver-operating characteristic curves to predict each outcome