Variables

2011-2012

2015-2016

*p1

*p2

*p3

Total

N = 2043

Episiotomy

n = 1214

No Episiotomy

n = 829

Total

n = 2225

Episiotomy

n = 983

No Episiotomy

n = 1242

Age (in years)—md [95% CI]

24.00 [24.66 - 25.23]

22.00 [26.69 - 27.60]a

26.00 [26.69 - 27.60]b

24.00 [24.88 - 25.44]

22.00 [23.13 - 23.90]a

26.00 [26.19 - 26.96]b

0.204

≤0.0001

≤0.0001

Number of Previous Gestations—md [95% CI]

2.00 [2.20 - 2.38]

1.00 [1.59 - 1.81]a

3.00 [3.06 - 3.33]b

2.00 [2.02 - 2.13]

1.00 [1.44 - 1.54]c

2.00 [2.48 - 2.65]d

0.004

≤0.0001

≤0.0001

Number of Previous Deliveries—md [95% CI]

1.00 [0.91 - 1.04]

0.00 [0.37 - 0.46]a

1.00 [1.72 - 1.95]b

0.00 [0.74 - 0.84]

0.00 [0.21 - 0.28]c

1.00 [1.17 - 1.32]d

≤0.0001

≤0.0001

≤0.0001

Number of Previous Cesareans—md [95% CI]

0.00 [0.06 - 0.09]

0.00 [0.06 - 0.09]

0.00 [0.05 - 0.09]

0.00 [0.07 - 0.10]

0.00 [0.07 - 0.10]

0.00 [0.07 - 0.10]

0.241

0.803

0.707

Number of Previous Abortions#—md [95% CI]

0.00 [0.18 - 0.24]

0.00 [0.13 - 0.19]a

0.00 [0.23 - 0.33]b

0.00 [0.18 - 0.22]

0.00 [0.13 - 0.19]ac

0.00 [0.21 - 0.27]bd

0.553

≤0.0001

≤0.0001

Weight (in kg)—md [95% CI]

75.00 [75.97 - 77.21]

74.40 [74.93 - 76.50]a

76.10 [77.01 - 79.03]bc

76.50 [78.05 - 79.37]

75.00 [76.03 - 77.92]ab

78.00 [79.27 - 81.08]c

≤0.0001

≤0.0001

≤0.0001

BMI (in kg/m2)— md [95% CI]

29.10 [29.43 - 29.87]

28.60 [28.93 - 29.48]a

29.70 [29.97 - 30.69]b

29.50 [29.94 - 30.40]

29.00 [29.28 - 29.94]a

30.00 [30.32 - 30.96]b

0.009

≤0.0001

≤0.0001

GA (in weeks)—md [95% CI]

39.43 [39.12 - 39.26]

39.43 [39.18 - 39.36]ab

39.29 [38.95 - 39.19]a

39.43 [39.15 - 39.29]

39.57 [39.22 - 39.44]b

39.43 [39.03 - 39.23]a

0.333

≤0.0001

0.001

Ethnicity—n (n%)

White

Not white

1511 (74.0)

532 (26.0)

927 (76.4)

287 (23.6)

584 (70.4)

244 (29.6)

1689 (76.0)

534 (24.0)

782 (79.6)

201 (20.4)

907 (73.1)

333 (26.9)

0.137

≤0.0001

≤0.0001