LIMITATIONS OF THE MODIFIED ROBSON CRITERIA
1 . This classification does not allow the analysis of Caesarean section by demand and indicated Caesarean section for specific conditions (e .g ., placenta previa) .
2 . This classification does not account for pre-existing medical, surgical or fetal disease; indications for and methods used for induction of labour; and degrees of prematurity, all of which may influence the rate of Caesarean section .
3 . Group 5 includes 2 quite different groups: (1) those who planned or needed a repeat Caesarean section, and (2) those who attempted VBAC and required Caesarean section .
This classification system should be considered flexible . Interested parties may choose to further sub-classify the major categories to address specific research and clinical issues .