Table 5.

Cases of Instrumental Delivery Compared to Cases of Direct Second-Stage Cesarean Delivery (where no instrument was applied)

Variable	Odds Ratio (95% CI)
Birth weight (per 100g increase)	1.07 (1.05 – 1.09)*
Maternal age	1.03 (1.01 – 1.05)†
Ethnicity - Caucasian	Ref
Ethnicity - Black	0.81 (0.24 – 2.03)
Ethnicity – Southeast Asian	1.34 (0.86 – 2.00)
Ethnicity - Chinese	0.93 (0.35 – 2.21)
Ethnicity – other/unknown	0.88 (0.42 – 1.64)
Time at full dilation	0.1- (0.1 – 1.00)
Maternal BMI	1.00 (0.1 – 1.00)
Parity	1.08 (0.94 – 1.24)
Accoucheur	1.11 (0.95 – 1.30)
Delivery during daylight hours	0.86 (0.70 – 1.04)
Epidural anaesthesia	1.46 (1.18 – 1.81)*

Multivariate analysis was performed using a binomial logistic regression model. Model coefficients are expressed as odds ratios and 95% confidence intervals (CI).

Levels of significance:

^*p<0.001;

^†p<0.01.

CI, confidence interval; BMI, body mass index.

Associations that meet the threshold for statistical significance (alpha-level = 0.05) are shown in boldface.