From: Induction of labour in mid-trimester pregnancy using double-balloon catheter placement within 12 h versus within 12–24 h
n
0(cm)
1(cm)
2(cm)
≥3(cm)
12 h-DBC
31
10
9
2
24 h-DBC
27
3
7
8
Z
−2.185
P
0.029