A new classification allowing assessment of instrumental vaginal-birth practices

Instrumental vaginal birth, a very common intervention in obstetrics, concerns nearly one in eight women in France. Instrumentally assisted vaginal childbirth can be for maternal and/or fetal indications. Although it reduces recourse to caesarean section, it is subject to risks. Practices concerning instrumental birth are disparate, varying among different practitioners, maternity units and countries, and it is essential to be able to evaluate them. Our objective was to create a classification tool of women requiring instrumental birth to facilitate the analysis of practices within our maternity unit as well as to enable temporal and geographical comparisons.

We propose a simple and robust classification based on the same principles as Robson's classification. It is made up of seven totally inclusive and mutually exclusive groups. Our classification was refined and validated using the Delphi method by a panel of 14 experts from throughout France, and tested in our maternity unit using data from throughout 2021.

The seven clinically relevant groups are based on five obstetric criteria (multiplicity, presentation, gestational age, previous type of birth, induction of labor). To classify each woman in a group, five successive questions are posed in a predefined order. The classification has been validated by the experts with highly satisfactory overall agreement.

In order to improve the quality of care, we propose a tool to standardize the evaluation of instrumental vaginal birth practice (called the "Isère classification", after the county where we work in south-eastern France). It will also facilitate the comparison the practices among different maternity units in a network, a country or even among different countries.