Table 6 Unadjusted and adjusted odds ratios for the risk of second-degree perineal tear and obstetric anal sphincter injury by delivery mode and fetal weight

Spontaneous delivery and fetal weight < 4000 g (n = 335)

126

Reference

Reference

14

Reference

Reference

Spontaneous delivery and fetal weight ≥ 4000 g (n = 49)

24

2.32 (1.19, 4.54)*

2.22 (1.1, 4.51)*

9

7.83 (2.94, 20.9)

7.7 (2.71, 21.8)*

Vacuum extraction and fetal weight < 4000 g (n = 45)

23

2.22 (1.13, 4.37)*

2.41 (1.16, 5.02)*

6

5.22 (1.77, 15.4)*

5.52 (1.62, 18.8)*

Vacuum extraction and fetal weight ≥ 4000 g (n = 17)

9

4.64 (1.23, 17.5)*

4.8 (1.20, 19.3)*

2

9.29 (1.43, 60.2)*

12.7 (1.65, 97.7)*