Table 1 Characteristics of women who underwent non-operative vaginal deliveries

Maternal agel (years)

29 +/−  5

30 +/− 5

29 +/−  5

30 +/− 5

29 +/−  5

30 +/−5

29 +/− 5

30 +/−5

29 +/− 5

30 +/− 5

29 +/−  5

30 +/− 5

29 +/−  5

30 +/− 5

29 +/−  5

30 +/− 5

Primiparous women ^{* £}

60.6

31.6

61.3

32

62.7

32.7

63.8

32.8

63.9

32.1

64.1

31.7

64.1

31.5

64,0

31.6

Multiple pregnancies^£

1.1

0.8

1.1

0.8

1.1

0.7

1.1

0.8

1.1

0.8

1.1

0.8

1,0

0.8

1.1

0.8

Breech vaginal delivery ^£

2.1

1.2

2.1

1.3

2.1

1.3

2.2

1.3

2.2

1.4

2.2

1.4

2.3

1.5

2.4

1.5

Perineal tears ^£ (third and fourth degrees)

0.4

0.2

0.5

0.3

0.5

0.3

0.5

0.3

0.6

0.3

0.6

0.3

0.7

0.4

0.8

0.4

  < 37 WA£

–

–

–

4.1

6.1

4

6.1

3.9

6.2

3.9

6.2

3.9

6.1

 37–41 WA£

–

–

–

95.1

93.3

95.1

93.2

95.2

93,0

95.2

93.1

95.2

93.2

  > 41 WA£

–

–

–

0.8

0.6

0.9

0.7

0.9

0.8

0.9

0.7

0.9

0.7