Average rate of dilatation of cervix in primigravida and multigravida (cm/hr.)

Between 4 - 6 cm dilatation

Between 6 - 10 cm dilatation

Spontaneous (n = 371)

1.72 (SD = 1.10)

3.44 (SD = 1.84)

Induced (n = 269)

1.68 (SD = 1.63)

2.69 (SD = 1.18)

95% CI = −0.252 to 0.172

t test = −0.370

P value = 0.711

95% CI = −1.001 to −0.499

t test = −5.86

P value = <0.0001