|
Characteristic
|
Number of women in group
|
Number of women who give birth in water
|
Rate of birth in water (%)
|
Crude OR (95% CI)
|
Adjusted OR (95% CI)
|
p (Wald test)
|
|---|
|
All women
|
46,088
|
6264
|
13.6
| | | |
|
Age
|
|
18–24
|
9569
|
993
|
10.4
|
0.78 (0.72,0.85)
|
0.76 (0.70,0.82)
|
< 0.001
|
|
25–29
|
13,810
|
1783
|
12.9
|
Ref
|
Ref
| |
|
30–34
|
14,359
|
2281
|
15.9
|
1.27 (1.19,1.36)
|
1.17 (1.09,1.25)
| |
|
35–39
|
7142
|
1103
|
15.4
|
1.23 (1.14,1.34)
|
1.12 (1.03,1.22)
| |
|
40–44
|
1208
|
104
|
8.6
|
0.64 (0.52,0.78)
|
0.60 (0.48,0.74)
| |
|
Maternal BMI
|
|
18.5–24.9
|
27,011
|
3890
|
14.4
|
Ref
|
Ref
|
< 0.001
|
|
25.0–29.9
|
13,698
|
1818
|
13.3
|
0.91 (0.86,0.97)
|
0.98 (0.92,1.04)
| |
|
30–34.9
|
5379
|
556
|
10.3
|
0.69 (0.62,0.75)
|
0.77 (0.70,0.85)
| |
|
Parity
|
|
0
|
17,206
|
2393
|
13.9
|
Ref
|
Ref
| |
|
1
|
18,914
|
2835
|
15.0
|
1.09 (1.03,1.16)
|
1.01 (0.95,1.08)
| |
|
2
|
6691
|
798
|
11.9
|
0.84 (0.77,0.91)
|
0.86 (0.79,0.94)
| |
|
3+
|
3277
|
238
|
7.3
|
0.48 (0.42,0.56)
|
0.56 (0.47,0.66)
| |
|
Ethnicity
|
|
White
|
37,581
|
5793
|
15.4
|
Ref
|
Ref
|
< 0.001
|
|
Black
|
2339
|
139
|
5.9
|
0.35 (0.29,0.41)
|
0.42 (0.35, 0.50)
| |
|
Asian
|
4506
|
189
|
4.2
|
0.24 (0.21,0.28)
|
0.26 (0.23,0.30)
| |
|
Other
|
143
|
143
|
8.6
|
0.52 (0.43,0.61)
|
0.56 (0.47,0.66)
| |
|
Socioeconomic status
|
|
Least deprived = 1
|
9450
|
1787
|
18.9
|
Ref
|
Ref
|
< 0.001
|
|
2
|
7278
|
1180
|
16.2
|
0.83 (0.77,0.90)
|
0.89 (0.82, 0.96)
| |
|
3
|
10,120
|
1448
|
14.3
|
0.72 (0.66, 0.77)
|
0.81 (0.75, 0.87)
| |
|
4
|
10,049
|
1140
|
11.3
|
0.55 (0.51,0.59)
|
0.68 (0.62, 0.74)
| |
|
Most deprived = 5
|
9191
|
709
|
7.7
|
0.36 (0.33,0.39)
|
0.47 (0.43, 0.52)
| |
|
Birthweight
|
|
< 2500 g
|
594
|
15
|
2.5
|
0.17 (0.10,0.28)
|
0.19 (0.11, 0.32)
|
< 0.001
|
|
2500-4000 g
|
40,204
|
5385
|
13.4
|
Ref
|
Ref
| |
|
> 4000 g
|
5290
|
864
|
16.3
|
1.26 (1.17,1.37)
|
1.12 (1.03,1.21)
| |
- This table shows the rate of waterbirth in 46,088 women who had an unassisted vaginal birth in England in 2015/16 according to maternal and obstetric risk factors
