Risk Factor

Odds Ratio (95% Confidence Interval)

p-value

Age (per year)

1.093 (1.012, 1.180)

0.023

Second stage (per 15-min)

1.039 (0.989, 1.092)

0.129

Active pushing (per 15-min)

1.089 (1.005, 1.180)

0.038

Passive pushing (per 15-min)

1.027 (0.938, 1.125)

0.561

Baby’s head circumference (per 1-cm increase)

1.014 (0.796, 1.291)

0.910

Baby’s weight (per 100-gram increase)

0.996 (0.926, 1.072)

0.906

Epidural yes vs. no

0.584 (0.214, 1.593)

0.293

Episiotomy yes vs. no

2.708 (0.986,7.433)

0.053

Vacuum yes vs. no

0.983 (0.156, 6.182)

0.986

Oxytocin yes vs. no

0.833 (0.352, 1.970)

0.677

Anal tear yes vs. no

1.211 (0.453, 3.234)

0.703