Table 2

Risk factors of deep perineal tear

Risk factors
Univariate analysis RR (95% CI)
Multivariate analysis RR (95% CI)

Midline episiotomy
2.12 (1.52, 2.96)*
1.94 (1.25, 2.99)*
Maternal age > 35 yrs., < 20 yrs.
0.81 (0.49, 1.33)
0.94 (0.56, 1.59)
Primiparity
3.47 (2.27, 5.31)*
3.56 (2.23, 5.69)*
Gestational age > 41 wks.
0 (α, α)
8.39 (0, α)
Maternal height ≤ 145 cm.
2.60 (1.19, 5.67)*
4.22 (2.01, 8.44)*
Maternal body mass index > 25
0.94 (0.65, 1.36)
1.01 (0.96, 1.06)
Baby birth weight > 3500 gm.
1.51 (0.99, 2.27)
2.22 (1.46, 3.38)*
Experienced Physician


     1. intern
2.50 (0, α)
9.45 (0, α)
     2. resident
0.48 (0.34, 0.67)
0.69 (0.44, 1.08)
     3. staff
1
1
Operative vaginal delivery


     1. vacuum extraction
1.92 (1.17, 3.15)*
1.12 (0.62, 2.00)
     2. forceps extraction
4.04 (2.70, 6.04)*
2.82 (1.89, 4.19)*
     3. normal vg. Delivery
1
1
Duration of second stage > 60 min
2.30 (1.17, 4.54)*
1.69 (0.81, 3.54)

*statistically significant

Sooklim et al. Reproductive Health 2007 4:10   doi:10.1186/1742-4755-4-10