Use of the Robson Ten Group Classification System to categorise operative vaginal delivery

Operative vaginal delivery (OVD), either vacuum or forceps, can be used to expedite vaginal delivery. While rates of OVD have been reducing worldwide, rates in Ireland remain high. The Robson Ten Group Classification System (TGCS) was originally created to compare rates of caesarean delivery between healthcare units, although no similar system exists for the analysis of OVD.

We sought to examine rates of OVD using the TGCS in an effort to understand which patient groups make significant contributions to the overall rate of OVD.

This is a retrospective cohort study of all women delivering in a tertiary-level university institution in Dublin, Ireland, from 2007 to 2016. Mode of delivery for all patients was extracted from contemporaneously recorded hospital records. Rates of OVD were analysed according to the TGCS, and the contribution of each group to the overall hospital population was calculated.

There were 86 191 deliveries of women in our institution, of which 19.3% (16 673/86 191) had an OVD. Women in Group 1 (singleton, cephalic, nulliparous women at term in spontaneous labour) contributed the most to the overall rate of OVD, accounting for almost half of all OVDs (46.1% (7679/16 673)). Nulliparous women with a singleton, cephalic fetus at term who were induced (Group 2) were more likely to have an OVD than similar patients who laboured spontaneously (Group 1).

OVD accounts for almost one in five deliveries in our population and is predominately performed in nulliparous women. These groups may be the subject of interventions to lower rates of OVD. The Robson TGCS is a freely available tool to hospitals and birthing centres to facilitate comparison of rates of OVD on local and national levels.