Table 1: 10-group classification. Groups 2 and 4 were further divided respectively in to 2a, 2b and 4a, 4b.

GroupClassification

1Nulliparous, single cephalic, ≥37 weeks, in spontaneous labour
2aNulliparous, single cephalic, ≥37 weeks, induced labour
2bNulliparous, single cephalic, ≥37 weeks, CD before labour
3Multiparous (excluding previous CD), single cephalic, ≥37 weeks, in spontaneous labour
4aMultiparous (excluding previous CD), single cephalic, ≥37 weeks, induced labour
4bMultiparous (excluding previous CD), single cephalic, ≥37 weeks, CD before labour
5Previous CD, single cephalic, ≥37 weeks
6All nulliparous breeches
7All multiparous breeches (including previous CD)
8All multiple pregnancies (including previous CD)
9All transverse/oblique lies (including previous CD)
10All preterm single cephalic, <37 weeks, including previous CD

CD: caesarean delivery.