Table 4 Characteristics of women in the included studies
Characteristics of women | Number of studies | % |
|---|---|---|
Population | Â | Â |
Women giving birth vaginally or women in labour | 76 | 95.0 |
Women undergoing vacuum extraction | 2 | 2.5 |
Women undergoing induction of labour | 1 | 1.3 |
Women with prolonged second stage of labour | 1 | 1.3 |
Number of fetuses | Â | Â |
Singleton only | 29 | 36.3 |
Twins only | 1 | 1.3 |
Singletons and multiples | 6 | 7.5 |
Not specified | 44 | 55.0 |
Parity | Â | Â |
Nulliparous women only | 11 | 13.8 |
Any parity | 39 | 48.8 |
Any parity except grandmultiparas | 1 | 1.3 |
Not specified | 29 | 36.3 |